( 2 ) year-end rig count as reported by baker hughes incorporated - worldwide rig count . ( 3 ) average daily and year-end west texas intermediate crude spot price as reported by the u.s. energy information administration . ( 4 ) average daily and year-end europe brent crude spot price as reported by the u.s. energy information administration . ( 5 ) average daily and year-end henry hub natural gas spot price as reported by the u.s. energy information administration . 19 the prices for both wti and brent crude oil began to weaken after the opec meeting held in november 2014. average prices for the majority of the 2014 calendar year were in excess of $ 99 per barrel for wti and in excess of $ 105 per barrel for brent ; however , both were down to approximately $ 55 per barrel by the end of 2014 and less than $ 40 per barrel by the end of 2015. the volatility and significant reduction in the average price of crude oil during 2015 and 2016 resulted in a significant decrease in the activities associated with both the exploration and production of oil during 2015 and throughout most of 2016. however , crude oil prices , although still volatile , began to improve during the second half of 2016 and continued to strengthen during 2017 , especially during the second half of 2017. on average , pricing for crude oil improved over 16 % for 2017 over 2016 , which resulted in much improved levels of land-based activity associated with the exploration and production of oil in the united states . in north america , the land-based rig count decreased 62 % during 2015 and another 53 % during the first half of 2016 , which greatly impacted both services and product sales to this market over this time period . although the north america rig count improved at the end of 2016 it still remained almost 20 % below 2015 levels and continued to strengthen throughout most of 2017. we saw resilient levels of activities on development projects and producing fields in the u.s. unconventional reservoirs during the second half of 2016 which continued and expanded during 2017 as we began the recovery phase of this business cycle . outside of north america , activities associated with the exploration for and production of oil have also decreased from 2014 levels , although not as significantly as the land-based activities in north america . our clients ' activities in the international and deepwater markets declined during 2015 and 2016 and remained at these lower levels in 2017 ; however , we believe these markets have shown signs of recovery as our clients have announced several new major capital projects . results of operations operating results for the year ended december 31 , 2017 compared to the years ended december 31 , 2016 and 2015 we evaluate our operating results by analyzing revenue , operating income and net income margin ( defined as net income divided by total revenue ) . since we have a relatively fixed cost structure , increases in revenue generally translate into higher operating income results as well as net income margin percentages . results for the years ended december 31 , 2017 , 2016 and 2015 are summarized in the following chart : 20 results of operations as a percentage of applicable revenue are as follows ( dollars in thousands ) : replace_table_token_4_th services revenue services revenue increased to $ 481.5 million in 2017 from $ 470.3 million in 2016 ; however , services revenue for 2016 decreased from $ 612.0 million in 2015 . the upward trend in the average price of crude oil during 2017 resulted in continued strengthening of activities associated with the exploration and production of oil during the second half of 2017. however , the most significant increase was realized in onshore activities within the united states while the decrease in international activities continued during most of 2017. average prices for wti crude oil increased 17 % in 2017 compared to an 11 % decrease in 2016 and average prices for brent crude oil increased by 24 % in 2017 compared to a 17 % decrease in 2016. as a result , the average global rig count climbed 27 % in 2017 compared to a decline of 32 % in 2016 , primarily driven by increases in the north american rig count . over this same time period , our service revenue increased slightly by 2.4 % in 2017 compared to 2016 and decreased only 23 % in 2016 compared to 2015 , as demand for our analytical , diagnostic , and completion services was less impacted by the significant decrease in drilling activities . wells must be drilled and or completed , stimulated , cored and have reservoir fluid samples collected , before we see the benefits of the increased commodity prices . the improvements in global crude oil prices during 2017 are positive indicators of a balancing market and support for future investments , as we continued our focus on worldwide crude oil related projects , including those related to the development of fields offshore south america and in the middle east . product sales revenue product sales revenue , which is tied more to completions in north america , increased 43 % to $ 178.3 million in 2017 from $ 124.5 million in 2016 ; however , product sales revenue for 2016 decreased from $ 185.6 million in 2015 .the average rig count for the u.s. and canada increased 38 % during 2017 compared to a 45 % decrease in 2016. the 43 % increase in product sales revenue outpaced the rig count increase due to our differentiated well completion product sales surpassing the industry activity levels in north america . story_separator_special_tag based on recent developments , and modest strengthening in the price of crude oil and natural gas , we believe that the level of activities and workflows experienced in 2017 will continue into 2018 and will strengthen for north america . additionally , we believe the trend in recent public announcements of major offshore and international projects by our clients will continue , and these announcements are signs that a recovery of the offshore deepwater and international markets are also improving . an increase in the activities in these markets could positively impact our revenues , operating income and operating margins as well . we expect to meet ongoing working capital needs , capital expenditure requirements and funding of our dividend and share repurchase programs from a combination of cash on hand , cash flow from operating activities and available borrowings under our credit facility . critical accounting estimates the preparation of financial statements in accordance with u.s. gaap requires us to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period . we evaluate our estimates on an ongoing basis and determine the adequacy of our estimates based on our historical experience and various other assumptions that we believe are reasonable under the circumstances . by nature , these judgments are subject to an inherent degree of uncertainty . we consider an accounting estimate to be critical if it is highly subjective and if changes in the estimate 28 under different assumptions would result in a material impact on our financial condition and results of operations . the following transaction types require significant judgment and , therefore , are considered critical accounting policies as of december 31 , 2017 . allowance for doubtful accounts we evaluate whether client receivables are collectible . we perform ongoing credit evaluations of our clients and monitor collections and payments in order to maintain a provision for estimated uncollectible accounts based on our historical collection experience and our current aging of client receivables outstanding in addition to clients ' representations and our understanding of the economic environment in which our clients operate . based on our review , we establish or adjust allowances for specific clients and the accounts receivable as a whole . our allowance for doubtful accounts decreased to $ 2.6 million as of december 31 , 2017 , compared to $ 3.1 million as of december 31 , 2016 . income taxes our income tax expense includes income taxes of the netherlands , the u.s. and other foreign countries as well as local , state and provincial income taxes . we recognize deferred tax assets or liabilities for the differences between the financial statement carrying amount and tax basis of assets and liabilities using enacted tax rates in effect for the years in which the asset is recovered or the liability is settled . we estimate the likelihood of the recoverability of our deferred tax assets ( particularly , net operating loss carry-forwards ) . any valuation allowance recorded is based on estimates and assumptions of taxable income into the future and a determination is made of the magnitude of deferred tax assets which are more likely than not to be realized . valuation allowances of our net deferred tax assets aggregated to $ 8.2 million and $ 10.0 million at december 31 , 2017 and 2016 , respectively . if these estimates and related assumptions change in the future , we may be required to record additional valuation allowances against our deferred tax assets and our effective tax rate may increase which could result in a material adverse effect on our financial position , results of operations and cash flows . we have not provided for deferred taxes on the unremitted earnings of certain subsidiaries that we consider to be indefinitely reinvested . should we make a distribution of the unremitted earnings of these subsidiaries , we may be required to record additional taxes . we record a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in our tax return . we also recognize interest and penalties , if any , related to unrecognized tax benefits in income tax expense . long-lived assets , intangibles and goodwill property , plant and equipment are carried at cost less accumulated depreciation . major renewals and improvements are capitalized while maintenance and repair costs are charged to expense as incurred . they are depreciated using the straight-line method based on their individual estimated useful lives , except for leasehold improvements , which are depreciated over the remaining lease term , if shorter . we estimate the useful lives and salvage values of our assets based on historical data of similar assets . when long-lived assets are sold or retired , the remaining costs and related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in income . these capitalized long-lived assets could become impaired if our operating plans or business environment changes . intangible assets , including patents , trademarks , and trade names , are carried at cost less accumulated amortization . intangibles with determinable lives are amortized using the straight-line method based on the estimated useful life of the intangible . intangibles with indeterminable lives , which consist primarily of corporate trade names , are not amortized , but are tested for impairment annually or whenever events or changes in circumstances indicate that impairment is possible . we review our long-lived assets , including definite-lived intangible assets , for impairment when events or changes in circumstances indicate that their net book value may not be recovered over their remaining service lives . indicators of possible impairment may include significant declines in activity levels in regions where specific assets or groups of assets are located , extended periods of

cash flows the following table summarizes cash flows for the years ended december 31 , 2017 , 2016 and 2015 ( in thousands ) : replace_table_token_9_th the decrease in cash provided by operating activities in 2017 compared to 2016 was primarily due to increases in working capital , offset by an increase in net income while the decrease in cash provided by operations in 2016 compared to 2015 was primarily attributable to the industry downturn resulting in a year-over-year decrease in net income , partially offset by reductions in working capital . cash flow used in investing activities in 2017 increased $ 5.8 million compared to 2016 primarily as a result of increased capital expenditures . cash flow used in investing activities in 2016 decreased $ 24.9 million compared to 2015 primarily as a result of a $ 13.8 million acquisition in 2015 and lower capital expenditures in 2016. cash flow used in financing activities in 2017 decreased $ 20.8 million compared to 2016 . cash flow used in financing activities in 2016 decreased $ 55.4 million compared to 2015 . during 2017 , we used $ 16.9 million to repurchase our common shares , $ 97.1 million to pay dividends , and increased our debt balance by $ 10 million . during 2016 , we used $ 7.2 million to repurchase our common shares , $ 95.1 million to pay dividends , and decreased our debt balance by $ 215 million through the issuance of new shares . during 2015 , we used $ 159.7 million to repurchase our common shares and $ 94.2 million to pay dividends , offset by an increase in our debt balance of $ 77 million . during the year ended december 31 , 2017 , we repurchased 158,569 shares of our common stock for an aggregate amount of $ 16.9 million , or an average price of $ 106.63 per share . the repurchase of shares in the open market is at the discretion of management pursuant to shareholder authorization .


 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.
     ```cash flows the following table summarizes cash flows for the years ended december 31 , 2017 , 2016 and 2015 ( in thousands ) : replace_table_token_9_th the decrease in cash provided by operating activities in 2017 compared to 2016 was primarily due to increases in working capital , offset by an increase in net income while the decrease in cash provided by operations in 2016 compared to 2015 was primarily attributable to the industry downturn resulting in a year-over-year decrease in net income , partially offset by reductions in working capital . cash flow used in investing activities in 2017 increased $ 5.8 million compared to 2016 primarily as a result of increased capital expenditures . cash flow used in investing activities in 2016 decreased $ 24.9 million compared to 2015 primarily as a result of a $ 13.8 million acquisition in 2015 and lower capital expenditures in 2016. cash flow used in financing activities in 2017 decreased $ 20.8 million compared to 2016 . cash flow used in financing activities in 2016 decreased $ 55.4 million compared to 2015 . during 2017 , we used $ 16.9 million to repurchase our common shares , $ 97.1 million to pay dividends , and increased our debt balance by $ 10 million . during 2016 , we used $ 7.2 million to repurchase our common shares , $ 95.1 million to pay dividends , and decreased our debt balance by $ 215 million through the issuance of new shares . during 2015 , we used $ 159.7 million to repurchase our common shares and $ 94.2 million to pay dividends , offset by an increase in our debt balance of $ 77 million . during the year ended december 31 , 2017 , we repurchased 158,569 shares of our common stock for an aggregate amount of $ 16.9 million , or an average price of $ 106.63 per share . the repurchase of shares in the open market is at the discretion of management pursuant to shareholder authorization .
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 Suspicious Activity Report : ( 2 ) year-end rig count as reported by baker hughes incorporated - worldwide rig count . ( 3 ) average daily and year-end west texas intermediate crude spot price as reported by the u.s. energy information administration . ( 4 ) average daily and year-end europe brent crude spot price as reported by the u.s. energy information administration . ( 5 ) average daily and year-end henry hub natural gas spot price as reported by the u.s. energy information administration . 19 the prices for both wti and brent crude oil began to weaken after the opec meeting held in november 2014. average prices for the majority of the 2014 calendar year were in excess of $ 99 per barrel for wti and in excess of $ 105 per barrel for brent ; however , both were down to approximately $ 55 per barrel by the end of 2014 and less than $ 40 per barrel by the end of 2015. the volatility and significant reduction in the average price of crude oil during 2015 and 2016 resulted in a significant decrease in the activities associated with both the exploration and production of oil during 2015 and throughout most of 2016. however , crude oil prices , although still volatile , began to improve during the second half of 2016 and continued to strengthen during 2017 , especially during the second half of 2017. on average , pricing for crude oil improved over 16 % for 2017 over 2016 , which resulted in much improved levels of land-based activity associated with the exploration and production of oil in the united states . in north america , the land-based rig count decreased 62 % during 2015 and another 53 % during the first half of 2016 , which greatly impacted both services and product sales to this market over this time period . although the north america rig count improved at the end of 2016 it still remained almost 20 % below 2015 levels and continued to strengthen throughout most of 2017. we saw resilient levels of activities on development projects and producing fields in the u.s. unconventional reservoirs during the second half of 2016 which continued and expanded during 2017 as we began the recovery phase of this business cycle . outside of north america , activities associated with the exploration for and production of oil have also decreased from 2014 levels , although not as significantly as the land-based activities in north america . our clients ' activities in the international and deepwater markets declined during 2015 and 2016 and remained at these lower levels in 2017 ; however , we believe these markets have shown signs of recovery as our clients have announced several new major capital projects . results of operations operating results for the year ended december 31 , 2017 compared to the years ended december 31 , 2016 and 2015 we evaluate our operating results by analyzing revenue , operating income and net income margin ( defined as net income divided by total revenue ) . since we have a relatively fixed cost structure , increases in revenue generally translate into higher operating income results as well as net income margin percentages . results for the years ended december 31 , 2017 , 2016 and 2015 are summarized in the following chart : 20 results of operations as a percentage of applicable revenue are as follows ( dollars in thousands ) : replace_table_token_4_th services revenue services revenue increased to $ 481.5 million in 2017 from $ 470.3 million in 2016 ; however , services revenue for 2016 decreased from $ 612.0 million in 2015 . the upward trend in the average price of crude oil during 2017 resulted in continued strengthening of activities associated with the exploration and production of oil during the second half of 2017. however , the most significant increase was realized in onshore activities within the united states while the decrease in international activities continued during most of 2017. average prices for wti crude oil increased 17 % in 2017 compared to an 11 % decrease in 2016 and average prices for brent crude oil increased by 24 % in 2017 compared to a 17 % decrease in 2016. as a result , the average global rig count climbed 27 % in 2017 compared to a decline of 32 % in 2016 , primarily driven by increases in the north american rig count . over this same time period , our service revenue increased slightly by 2.4 % in 2017 compared to 2016 and decreased only 23 % in 2016 compared to 2015 , as demand for our analytical , diagnostic , and completion services was less impacted by the significant decrease in drilling activities . wells must be drilled and or completed , stimulated , cored and have reservoir fluid samples collected , before we see the benefits of the increased commodity prices . the improvements in global crude oil prices during 2017 are positive indicators of a balancing market and support for future investments , as we continued our focus on worldwide crude oil related projects , including those related to the development of fields offshore south america and in the middle east . product sales revenue product sales revenue , which is tied more to completions in north america , increased 43 % to $ 178.3 million in 2017 from $ 124.5 million in 2016 ; however , product sales revenue for 2016 decreased from $ 185.6 million in 2015 .the average rig count for the u.s. and canada increased 38 % during 2017 compared to a 45 % decrease in 2016. the 43 % increase in product sales revenue outpaced the rig count increase due to our differentiated well completion product sales surpassing the industry activity levels in north america . story_separator_special_tag based on recent developments , and modest strengthening in the price of crude oil and natural gas , we believe that the level of activities and workflows experienced in 2017 will continue into 2018 and will strengthen for north america . additionally , we believe the trend in recent public announcements of major offshore and international projects by our clients will continue , and these announcements are signs that a recovery of the offshore deepwater and international markets are also improving . an increase in the activities in these markets could positively impact our revenues , operating income and operating margins as well . we expect to meet ongoing working capital needs , capital expenditure requirements and funding of our dividend and share repurchase programs from a combination of cash on hand , cash flow from operating activities and available borrowings under our credit facility . critical accounting estimates the preparation of financial statements in accordance with u.s. gaap requires us to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period . we evaluate our estimates on an ongoing basis and determine the adequacy of our estimates based on our historical experience and various other assumptions that we believe are reasonable under the circumstances . by nature , these judgments are subject to an inherent degree of uncertainty . we consider an accounting estimate to be critical if it is highly subjective and if changes in the estimate 28 under different assumptions would result in a material impact on our financial condition and results of operations . the following transaction types require significant judgment and , therefore , are considered critical accounting policies as of december 31 , 2017 . allowance for doubtful accounts we evaluate whether client receivables are collectible . we perform ongoing credit evaluations of our clients and monitor collections and payments in order to maintain a provision for estimated uncollectible accounts based on our historical collection experience and our current aging of client receivables outstanding in addition to clients ' representations and our understanding of the economic environment in which our clients operate . based on our review , we establish or adjust allowances for specific clients and the accounts receivable as a whole . our allowance for doubtful accounts decreased to $ 2.6 million as of december 31 , 2017 , compared to $ 3.1 million as of december 31 , 2016 . income taxes our income tax expense includes income taxes of the netherlands , the u.s. and other foreign countries as well as local , state and provincial income taxes . we recognize deferred tax assets or liabilities for the differences between the financial statement carrying amount and tax basis of assets and liabilities using enacted tax rates in effect for the years in which the asset is recovered or the liability is settled . we estimate the likelihood of the recoverability of our deferred tax assets ( particularly , net operating loss carry-forwards ) . any valuation allowance recorded is based on estimates and assumptions of taxable income into the future and a determination is made of the magnitude of deferred tax assets which are more likely than not to be realized . valuation allowances of our net deferred tax assets aggregated to $ 8.2 million and $ 10.0 million at december 31 , 2017 and 2016 , respectively . if these estimates and related assumptions change in the future , we may be required to record additional valuation allowances against our deferred tax assets and our effective tax rate may increase which could result in a material adverse effect on our financial position , results of operations and cash flows . we have not provided for deferred taxes on the unremitted earnings of certain subsidiaries that we consider to be indefinitely reinvested . should we make a distribution of the unremitted earnings of these subsidiaries , we may be required to record additional taxes . we record a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in our tax return . we also recognize interest and penalties , if any , related to unrecognized tax benefits in income tax expense . long-lived assets , intangibles and goodwill property , plant and equipment are carried at cost less accumulated depreciation . major renewals and improvements are capitalized while maintenance and repair costs are charged to expense as incurred . they are depreciated using the straight-line method based on their individual estimated useful lives , except for leasehold improvements , which are depreciated over the remaining lease term , if shorter . we estimate the useful lives and salvage values of our assets based on historical data of similar assets . when long-lived assets are sold or retired , the remaining costs and related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in income . these capitalized long-lived assets could become impaired if our operating plans or business environment changes . intangible assets , including patents , trademarks , and trade names , are carried at cost less accumulated amortization . intangibles with determinable lives are amortized using the straight-line method based on the estimated useful life of the intangible . intangibles with indeterminable lives , which consist primarily of corporate trade names , are not amortized , but are tested for impairment annually or whenever events or changes in circumstances indicate that impairment is possible . we review our long-lived assets , including definite-lived intangible assets , for impairment when events or changes in circumstances indicate that their net book value may not be recovered over their remaining service lives . indicators of possible impairment may include significant declines in activity levels in regions where specific assets or groups of assets are located , extended periods of

