the extent to which covid-19 impacts our operations or financial results will further depend on future developments , which are highly uncertain and can not be predicted , including the status of state and local government reopening plans and any resurgence of illness and the reimposition of certain restrictions in connection therewith , additional actions taken by governments , businesses and individuals to contain the virus or address its impact , new information which may emerge concerning the severity or treatability of the virus , the successful rollout of vaccines , new strains of the virus , and the extent of the economic downturn resulting from the response to the virus , among others . overview we are a world leader in sensor systems that enhance perception and awareness . we were founded in 1978 and have since become a premier designer , manufacturer , and marketer of thermal imaging and other sensing products and systems . our advanced sensors and integrated sensor systems enable the gathering and analysis of critical information through a wide variety of applications in government , industrial and commercial markets worldwide . 37 our goal is to both enable our customers to benefit from the valuable information produced by advanced sensing technologies and to deliver sustained superior financial performance for our shareholders . we create value for our customers by improving personal and public safety and security , providing advanced intelligence , surveillance , reconnaissance , and tactical defense capabilities , facilitating air , ground , and maritime-based situational awareness , detecting electrical , mechanical and building envelope problems , displaying process irregularities , detecting volatile organic gas emissions , and enhancing advanced driver-assistance systems and autonomous driving solutions , as well as a variety of other uses of thermal and other sensing technologies . our business model and range of solutions allow us to sell products to various end markets , including industrial , original equipment manufacturing , military , homeland security , enterprise , infrastructure , and environmental end markets . we sell off-the-shelf products and customized solutions in configurations to suit specific customer requirements in an efficient , timely , and affordable manner , and support those customers with training and ongoing support and services . centered on the design of products for low-cost manufacturing and high-volume distribution , our commercial operating model has been developed over time and provides us with a unique ability to adapt to market changes and meet our customers ' needs . international revenue accounted for approximately 46 percent , 45 percent and 47 percent of our revenue in 2020 , 2019 and 2018 , respectively . we anticipate that international sales will continue to account for a significant percentage of revenue in the future . we have exposure to foreign exchange fluctuations and changing dynamics of foreign competitiveness based on variations in the value of the united states dollar relative to other currencies . factors contributing to this variability include significant manufacturing activity in europe , significant sales denominated in currencies other than the united states dollar , and cross currency fluctuations between such currencies as the united states dollar , european euro , swedish kronor and british pound sterling . the impact of those fluctuations is reflected throughout our consolidated financial statements , but in the aggregate , did not have a material impact on our results of operations in 2020. we experience fluctuations in orders and sales due to seasonal variations and customer sales cycles , such as the seasonal pattern of contracting by the united states and certain foreign governments , the desire of customers to take delivery of equipment prior to fiscal year ends due to funding considerations , and the tendency of commercial enterprises to fully utilize annual capital budgets prior to expiration . such events have resulted and could continue to result in fluctuations in quarterly results in the future . as a result of such quarterly fluctuations in operating results , we believe that quarter-to-quarter comparisons of our results of operations are not necessarily meaningful and should not be relied upon as indicators of future performance . we expect that macroeconomic factors , including fluctuations in spending by united states government agencies , rates of gdp growth in certain geographic markets , and fluctuations in foreign currency exchange rates , will continue to impact our financial results and may render predictions regarding future performance difficult to make . in addition , in 2019 we successfully concluded a few large multi-year programs that provided revenue contributions over the past several years . while we have successfully won new programs , these new programs require investments in research and development and compliance to be successful , and investments in these programs will not translate into significant corresponding revenue until 2021 and beyond . historically we have selectively pursued the acquisition of businesses and investments at attractive valuations that would expand or complement our current portfolio and allow access to new customers or technologies , and also have explored the divestiture of businesses that no longer meet our needs or strategy or that could perform better outside of our organization . in pursuing our business strategy , we routinely have conducted discussions , evaluated targets and entered into agreements regarding possible acquisitions , divestitures , ventures and equity investments . we continue to build upon our strong market position , meeting the needs of our wide range of customers and are investing for long-term growth through the execution of our strategic priorities . to better position us to deliver long-term growth we launched a strategy-driven restructuring plan ( `` project be ready `` ) in february 2020. this initiative simplified our product portfolio and better aligned resources with higher growth opportunities while reducing costs . we discontinued certain non-core consumer centric product lines within the outdoor and tactical systems business . story_separator_special_tag we intend to continue to have significant research and development expenses in the future to provide a continuing flow of innovative and high-quality products that maintain and enhance our competitive position in each of our business segments . we believe that future cash flow generation will be sufficient to support the development of new products that fuel the growth of the business . selling , general and administrative expenses . the decrease for the year ended december 31 , 2020 as compared to the year ended december 31 , 2019 was primarily due to operating expense reductions from project be ready , decreases in travel and marketing costs , reduced intangible asset amortization , lower asset impairment charges related to restructuring actions and a decrease in separation , transaction , and integration costs . the increase for the year ended december 31 , 2019 as compared to the year ended december 31 , 2018 was primarily attributed to acquisition related expenses for acquisitions occurring in the first half of 2019 , consent agreement related costs and goodwill and intangible asset impairment charges related to restructuring actions . restructuring expenses . we had various active restructuring programs focused on reorganization and discontinuation of certain businesses , targeted workforce reductions , and facility consolidation actions . in the first quarter of 2020 , we initiated a strategy-driven restructuring plan , project be ready , to simplify our product portfolio and better align resources with higher growth opportunities while reducing costs . project be ready included an organizational realignment , targeted workforce reductions , and facility optimization initiatives . all previously approved ongoing restructuring activities that were in process as of january 1 , 2020 were consolidated into project be ready . the net pre-tax restructuring charges recorded for these programs during the year ended december 31 , 2020 primarily represent employee separation costs and third party and other costs . during the years ended december 31 , 2019 and 2018 we also recorded net pre-tax restructuring charges in connection with other restructuring activities . refer to note 21 , `` restructuring `` of the notes to the consolidated financial statements in item 8 for further discussion . loss on sale of business . during the year ended december 31 , 2018 , as a result of the divestiture of our consumer and smb security business , net working capital adjustments , and subsequent negotiations with the buyer , we recognized an additional pre-tax loss of $ 13.7 million . interest expense . interest expense for the year ended december 31 , 2020 was associated with our previous 3.125 percent senior unsecured notes ( the “ 2021 notes ” ) in aggregate principal amount of $ 425.0 million and our 2.500 percent senior unsecured notes ( the “ 2030 notes ” ) in aggregate principal amount of $ 500.0 million that were issued and sold on august 3 , 2020 , as well as interest on amounts drawn under our credit facility . the 2021 notes were redeemed in full in connection with the august 2020 issuance of the 2030 notes in a public offering . 42 interest expense for the year ended december 31 , 2019 was associated with our 2021 notes as well as interest on amounts drawn under our credit facility . interest expense for the year ended december 31 , 2018 was primarily associated with the 2021 notes . loss on debt extinguishment . during the year ended december 31 , 2020 we recorded a $ 9.1 million loss on debt extinguishment due to the redemption of our 2021 notes , which consisted of a $ 8.5 million payment of redemption premium and $ 0.6 million for the unamortized portion of the original issue discount and previously incurred issuance costs . other ( income ) expense , net . the change in other ( income ) expense , net for the year ended december 31 , 2020 as compared to the year ended december 31 , 2019 was primarily attributable to increased gains on currency exchange rate fluctuations and increased gains on certain deferred compensation arrangements . the change in other ( income ) expense , net for the year ended december 31 , 2019 as compared to the year ended december 31 , 2018 was primarily attributable to impairments associated with our equity investments as well as minority investments losses . income taxes . our income tax provisions for the years ended december 31 , 2020 , 2019 and 2018 represented effective tax rates of 25.4 percent , 29.1 percent and 8.0 percent , respectively . our effective tax rate in 2020 was higher than the united states federal tax rate of 21.0 percent mainly due to state taxes , non-deductible expenses , accruals for unrecognized tax benefits and settlements with taxing authorities , and higher tax rates on income earned in foreign jurisdictions . these amounts were partially offset by tax credits generated in the united states and foreign jurisdictions . our effective tax rate in 2019 was higher than the united states federal tax rate of 21.0 percent mainly due to accruals for settlements with various taxing authorities , state taxes , additional withholding tax due on future distributions of foreign earnings included in the transition tax levied by the tax act , and higher tax rates on income earned in foreign jurisdictions . these amounts were offset by tax credits generated in the united states and foreign jurisdictions as well as excess tax benefits from stock compensation . our effective tax rate in 2018 was lower than the united states federal tax rate of 21.0 percent mainly due to recognition of previously unrecognized tax benefits relating to the european union state aid recovery , excess tax benefits from stock compensation and a reduction in the accrual for the united states transition tax , offset partially by state taxes , higher tax rates applied to income earned in certain foreign jurisdictions , and other discrete items

liquidity and capital resources overview at december 31 , 2020 , we had a total of $ 297.8 million in cash and cash equivalents , $ 88.8 million of which was in the united states and $ 209.0 million at our foreign subsidiaries . at december 31 , 2020 and december 31 , 2019 , we had outstanding debt of $ 738.4 million and $ 676.9 million , respectively , which consists of unsecured term loans and borrowings under the revolving credit facility that we entered into during 2019 ( collectively referred to as the `` credit agreement '' ) and senior unsecured notes . on august 3 , 2020 , we issued and sold our 2030 notes in an underwritten public offering . the aggregate net proceeds from the offering were approximately $ 494.2 million after deducting underwriting fees , debt discount and transaction issuance costs . interest on the 2030 notes is payable semiannually in arrears on february 1 and august 1 of each year beginning on february 1 , 2021. the net proceeds from the sale of the 2030 notes were used to redeem the 2021 notes , and for general corporate purposes , which may include funding for working capital , investments in our subsidiaries , capital expenditures , acquisitions , and stock repurchases . in connection with the redemption of the 2021 notes , during the third quarter of 2020 , we recorded a $ 9.1 million loss on debt extinguishment on the consolidated statements of income . the credit agreement contains one financial covenant that requires maintenance of a consolidated total leverage ratio with which we complied at december 31 , 2020. we had $ 14.1 million of letters of credit outstanding under the credit agreement at december 31 , 2020 , which reduced the total availability under the revolving commitments under the credit agreement . see note 11 , `` debt '' of the notes to the consolidated financial statements in item 8 for more details .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```liquidity and capital resources overview at december 31 , 2020 , we had a total of $ 297.8 million in cash and cash equivalents , $ 88.8 million of which was in the united states and $ 209.0 million at our foreign subsidiaries . at december 31 , 2020 and december 31 , 2019 , we had outstanding debt of $ 738.4 million and $ 676.9 million , respectively , which consists of unsecured term loans and borrowings under the revolving credit facility that we entered into during 2019 ( collectively referred to as the `` credit agreement '' ) and senior unsecured notes . on august 3 , 2020 , we issued and sold our 2030 notes in an underwritten public offering . the aggregate net proceeds from the offering were approximately $ 494.2 million after deducting underwriting fees , debt discount and transaction issuance costs . interest on the 2030 notes is payable semiannually in arrears on february 1 and august 1 of each year beginning on february 1 , 2021. the net proceeds from the sale of the 2030 notes were used to redeem the 2021 notes , and for general corporate purposes , which may include funding for working capital , investments in our subsidiaries , capital expenditures , acquisitions , and stock repurchases . in connection with the redemption of the 2021 notes , during the third quarter of 2020 , we recorded a $ 9.1 million loss on debt extinguishment on the consolidated statements of income . the credit agreement contains one financial covenant that requires maintenance of a consolidated total leverage ratio with which we complied at december 31 , 2020. we had $ 14.1 million of letters of credit outstanding under the credit agreement at december 31 , 2020 , which reduced the total availability under the revolving commitments under the credit agreement . see note 11 , `` debt '' of the notes to the consolidated financial statements in item 8 for more details .
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 Suspicious Activity Report : the extent to which covid-19 impacts our operations or financial results will further depend on future developments , which are highly uncertain and can not be predicted , including the status of state and local government reopening plans and any resurgence of illness and the reimposition of certain restrictions in connection therewith , additional actions taken by governments , businesses and individuals to contain the virus or address its impact , new information which may emerge concerning the severity or treatability of the virus , the successful rollout of vaccines , new strains of the virus , and the extent of the economic downturn resulting from the response to the virus , among others . overview we are a world leader in sensor systems that enhance perception and awareness . we were founded in 1978 and have since become a premier designer , manufacturer , and marketer of thermal imaging and other sensing products and systems . our advanced sensors and integrated sensor systems enable the gathering and analysis of critical information through a wide variety of applications in government , industrial and commercial markets worldwide . 37 our goal is to both enable our customers to benefit from the valuable information produced by advanced sensing technologies and to deliver sustained superior financial performance for our shareholders . we create value for our customers by improving personal and public safety and security , providing advanced intelligence , surveillance , reconnaissance , and tactical defense capabilities , facilitating air , ground , and maritime-based situational awareness , detecting electrical , mechanical and building envelope problems , displaying process irregularities , detecting volatile organic gas emissions , and enhancing advanced driver-assistance systems and autonomous driving solutions , as well as a variety of other uses of thermal and other sensing technologies . our business model and range of solutions allow us to sell products to various end markets , including industrial , original equipment manufacturing , military , homeland security , enterprise , infrastructure , and environmental end markets . we sell off-the-shelf products and customized solutions in configurations to suit specific customer requirements in an efficient , timely , and affordable manner , and support those customers with training and ongoing support and services . centered on the design of products for low-cost manufacturing and high-volume distribution , our commercial operating model has been developed over time and provides us with a unique ability to adapt to market changes and meet our customers ' needs . international revenue accounted for approximately 46 percent , 45 percent and 47 percent of our revenue in 2020 , 2019 and 2018 , respectively . we anticipate that international sales will continue to account for a significant percentage of revenue in the future . we have exposure to foreign exchange fluctuations and changing dynamics of foreign competitiveness based on variations in the value of the united states dollar relative to other currencies . factors contributing to this variability include significant manufacturing activity in europe , significant sales denominated in currencies other than the united states dollar , and cross currency fluctuations between such currencies as the united states dollar , european euro , swedish kronor and british pound sterling . the impact of those fluctuations is reflected throughout our consolidated financial statements , but in the aggregate , did not have a material impact on our results of operations in 2020. we experience fluctuations in orders and sales due to seasonal variations and customer sales cycles , such as the seasonal pattern of contracting by the united states and certain foreign governments , the desire of customers to take delivery of equipment prior to fiscal year ends due to funding considerations , and the tendency of commercial enterprises to fully utilize annual capital budgets prior to expiration . such events have resulted and could continue to result in fluctuations in quarterly results in the future . as a result of such quarterly fluctuations in operating results , we believe that quarter-to-quarter comparisons of our results of operations are not necessarily meaningful and should not be relied upon as indicators of future performance . we expect that macroeconomic factors , including fluctuations in spending by united states government agencies , rates of gdp growth in certain geographic markets , and fluctuations in foreign currency exchange rates , will continue to impact our financial results and may render predictions regarding future performance difficult to make . in addition , in 2019 we successfully concluded a few large multi-year programs that provided revenue contributions over the past several years . while we have successfully won new programs , these new programs require investments in research and development and compliance to be successful , and investments in these programs will not translate into significant corresponding revenue until 2021 and beyond . historically we have selectively pursued the acquisition of businesses and investments at attractive valuations that would expand or complement our current portfolio and allow access to new customers or technologies , and also have explored the divestiture of businesses that no longer meet our needs or strategy or that could perform better outside of our organization . in pursuing our business strategy , we routinely have conducted discussions , evaluated targets and entered into agreements regarding possible acquisitions , divestitures , ventures and equity investments . we continue to build upon our strong market position , meeting the needs of our wide range of customers and are investing for long-term growth through the execution of our strategic priorities . to better position us to deliver long-term growth we launched a strategy-driven restructuring plan ( `` project be ready `` ) in february 2020. this initiative simplified our product portfolio and better aligned resources with higher growth opportunities while reducing costs . we discontinued certain non-core consumer centric product lines within the outdoor and tactical systems business . story_separator_special_tag we intend to continue to have significant research and development expenses in the future to provide a continuing flow of innovative and high-quality products that maintain and enhance our competitive position in each of our business segments . we believe that future cash flow generation will be sufficient to support the development of new products that fuel the growth of the business . selling , general and administrative expenses . the decrease for the year ended december 31 , 2020 as compared to the year ended december 31 , 2019 was primarily due to operating expense reductions from project be ready , decreases in travel and marketing costs , reduced intangible asset amortization , lower asset impairment charges related to restructuring actions and a decrease in separation , transaction , and integration costs . the increase for the year ended december 31 , 2019 as compared to the year ended december 31 , 2018 was primarily attributed to acquisition related expenses for acquisitions occurring in the first half of 2019 , consent agreement related costs and goodwill and intangible asset impairment charges related to restructuring actions . restructuring expenses . we had various active restructuring programs focused on reorganization and discontinuation of certain businesses , targeted workforce reductions , and facility consolidation actions . in the first quarter of 2020 , we initiated a strategy-driven restructuring plan , project be ready , to simplify our product portfolio and better align resources with higher growth opportunities while reducing costs . project be ready included an organizational realignment , targeted workforce reductions , and facility optimization initiatives . all previously approved ongoing restructuring activities that were in process as of january 1 , 2020 were consolidated into project be ready . the net pre-tax restructuring charges recorded for these programs during the year ended december 31 , 2020 primarily represent employee separation costs and third party and other costs . during the years ended december 31 , 2019 and 2018 we also recorded net pre-tax restructuring charges in connection with other restructuring activities . refer to note 21 , `` restructuring `` of the notes to the consolidated financial statements in item 8 for further discussion . loss on sale of business . during the year ended december 31 , 2018 , as a result of the divestiture of our consumer and smb security business , net working capital adjustments , and subsequent negotiations with the buyer , we recognized an additional pre-tax loss of $ 13.7 million . interest expense . interest expense for the year ended december 31 , 2020 was associated with our previous 3.125 percent senior unsecured notes ( the “ 2021 notes ” ) in aggregate principal amount of $ 425.0 million and our 2.500 percent senior unsecured notes ( the “ 2030 notes ” ) in aggregate principal amount of $ 500.0 million that were issued and sold on august 3 , 2020 , as well as interest on amounts drawn under our credit facility . the 2021 notes were redeemed in full in connection with the august 2020 issuance of the 2030 notes in a public offering . 42 interest expense for the year ended december 31 , 2019 was associated with our 2021 notes as well as interest on amounts drawn under our credit facility . interest expense for the year ended december 31 , 2018 was primarily associated with the 2021 notes . loss on debt extinguishment . during the year ended december 31 , 2020 we recorded a $ 9.1 million loss on debt extinguishment due to the redemption of our 2021 notes , which consisted of a $ 8.5 million payment of redemption premium and $ 0.6 million for the unamortized portion of the original issue discount and previously incurred issuance costs . other ( income ) expense , net . the change in other ( income ) expense , net for the year ended december 31 , 2020 as compared to the year ended december 31 , 2019 was primarily attributable to increased gains on currency exchange rate fluctuations and increased gains on certain deferred compensation arrangements . the change in other ( income ) expense , net for the year ended december 31 , 2019 as compared to the year ended december 31 , 2018 was primarily attributable to impairments associated with our equity investments as well as minority investments losses . income taxes . our income tax provisions for the years ended december 31 , 2020 , 2019 and 2018 represented effective tax rates of 25.4 percent , 29.1 percent and 8.0 percent , respectively . our effective tax rate in 2020 was higher than the united states federal tax rate of 21.0 percent mainly due to state taxes , non-deductible expenses , accruals for unrecognized tax benefits and settlements with taxing authorities , and higher tax rates on income earned in foreign jurisdictions . these amounts were partially offset by tax credits generated in the united states and foreign jurisdictions . our effective tax rate in 2019 was higher than the united states federal tax rate of 21.0 percent mainly due to accruals for settlements with various taxing authorities , state taxes , additional withholding tax due on future distributions of foreign earnings included in the transition tax levied by the tax act , and higher tax rates on income earned in foreign jurisdictions . these amounts were offset by tax credits generated in the united states and foreign jurisdictions as well as excess tax benefits from stock compensation . our effective tax rate in 2018 was lower than the united states federal tax rate of 21.0 percent mainly due to recognition of previously unrecognized tax benefits relating to the european union state aid recovery , excess tax benefits from stock compensation and a reduction in the accrual for the united states transition tax , offset partially by state taxes , higher tax rates applied to income earned in certain foreign jurisdictions , and other discrete items

