- 21 - depreciation and amortization represent depreciation of property and equipment , leasehold improvements and capitalized software costs . property , equipment and software are depreciated using t he straight-line method over their estimated useful lives , which range from 3 to 39 years . leasehold improvements are amortized using the straight-line method over the shorter of the lease term or estimated useful life . critical accounting policies and estimates we have identified the following accounting estimate as critical to our business and the understanding of our results of operations . for a detailed discussion of the application of this and other accounting policies , see “ note 1 - summary of operations and significant accounting policies ” to the consolidated financial statements incorporated into item 8 of part ii of this report . the preparation of this annual report on form 10-k requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements , and the reported amounts of revenue and expenses during the reporting period . management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances , the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources . actual results may differ from these estimates . workers ' compensation reserves we recognize our liability for the ultimate payment of incurred claims and claims adjustment expenses by establishing a reserve which represents our estimates of future amounts necessary to pay claims and related expenses with respect to workplace injuries that have occurred . when a claim involving a probable loss is reported , our independent third-party administrator for workers ' compensation claims ( “ tpa ” ) establishes a case reserve for the estimated amount of ultimate loss . the estimate reflects a judgment based on established case reserving practices and the experience and knowledge of the tpa regarding the nature and expected amount of the claim , as well as the estimated expenses of settling the claim , including legal and other fees and expenses of claims administration . the adequacy of such case reserves in part depends on the professional judgment of the tpa to properly and comprehensively evaluate the economic consequences of each claim . our reserves include an additional component for potential future increases in the cost to finally resolve open injury claims and claims incurred in prior periods but not reported ( together , `` ibnr `` ) based on actuarial estimates provided by the company 's independent actuary . ibnr reserves , unlike specific case reserves , do not apply to a specific claim but rather apply to the entire population of claims arising from a specific time period . ibnr primarily covers costs relating to : future claim payments in excess of case reserves on recorded open claims ; additional claim payments on closed claims ; and claims that have occurred but have not yet been reported to us . the process of estimating unpaid claims and claims adjustment expense involves a high degree of judgment and is affected by both internal and external events , including changes in claims handling practices , modifications in reserve estimation procedures , changes in individuals involved in the reserve estimation process , inflation , trends in the litigation and settlement of pending claims , and legislative changes . our estimates are based on informed judgment , derived from individual experiences and expertise applied to multiple sets of data and analyses . we consider significant facts and circumstances known both at the time that loss reserves are initially established and as new facts and circumstances become known . due to the inherent uncertainty underlying loss reserve estimates , the expenses incurred through final resolution of our liability for our workers ' compensation claims will likely vary from the related loss reserves at the reporting date . therefore , as specific claims are paid out in the future , actual paid losses may be materially different from our current loss reserves . - 22 - a basic premise in most actu arial analyses is that historical data and past patterns demonstrated in the incurred and paid historical data form a reasonable basis upon which to project future outcomes , absent a material change . significant structural changes to the available data can materially impact the reserve estimation process . to the extent a material change affecting the ultimate claim liability becomes known , such change is quantified to the extent possible through an analysis of internal company data and , if available and whe n appropriate , external data . actuaries exercise a considerable degree of judgment in the evaluation of these factors and the need for such actuarial judgment is more pronounced when faced with material uncertainties . we believe that the amounts recorded for our estimated liabilities for workers ' compensation claims , which are based on informed judgment , analysis of data , actuarial estimates , and analysis of other trends associated with the company 's historical universe of claims data , are reasonable . nevertheless , adjustments to such estimates will be required in future periods if the development of claim costs varies materially from our estimates and such future adjustments may be material to our results of operations . recent accounting pronouncements for a discussion of recent accounting pronouncements and their potential effect on the company 's results of operations and financial condition , see “ note 1 - summary of operations and significant accounting policies ” to the consolidated financial statements incorporated into item 8 of part ii of this report . story_separator_special_tag contractual obligations the company 's contractual obligations as of december 31 , 2018 are summarized below : replace_table_token_9_th inflation inflation generally has not been a significant factor in the company 's operations during the periods discussed above . the company has taken into account the impact of escalating medical and other costs in establishing reserves for future workers ' compensation claims payments . - 29 - item 7a . quantitative and qualitat ive disclosures about market risk the company 's exposure to market risk for changes in interest rates primarily relates to its investment portfolio and its outstanding borrowings on its line of credit and long-term debt . as of december 31 , 2018 , the company 's investments consisted principally of approximately $ 181.8 million in corporate bonds , $ 87.9 million in mortgage backed securities , $ 45.2 million in u.s. treasuries , $ 44.7 million in u.s. government agency securities , $ 4.7 million in supranational , $ 1.1 million in mutual funds , and $ 0.4 million in money market funds . the company 's outstanding debt totaled approximately $ 4.2 million at december 31 , 2018. based on the company 's overall interest exposure at december 31 , 2018 , a 50 basis point increase in market interest rates would have a $ 5.6 million effect on the fair value of the company 's investment portfolio . a 50 basis point increase would have an immaterial effect on the company 's outstanding borrowings because of the relative size of the outstanding borrowings . item 8. financial statements and supplementary data the consolidated financial statements and notes thereto required by this item begin on page f-1 of this report , as listed in item 15. item 9. changes in and disagreements with accountants on accounting and financial disclosure none . item 9a . controls and procedures evaluation of disclosure controls and procedures we maintain “ disclosure controls and procedures ” that are designed with the objective of providing reasonable assurance that information required to be disclosed in the reports we file or submit under the securities exchange act of 1934 , as amended ( the “ exchange act ” ) , is recorded , processed , summarized , and reported within the time periods specified in the sec 's rules and forms , and that such information is accumulated and communicated to our management , including our chief executive officer ( “ ceo ” ) and chief financial officer ( “ cfo ” ) , as appropriate , to allow timely decisions regarding required disclosure . in designing and evaluating our disclosure controls and procedures , our management recognizes that any controls and procedures , no matter how well designed and operated , can provide only reasonable assurance of achieving the desired control objectives , and our management is required to apply their judgment in evaluating the cost-benefit relationship of possible controls and procedures . based on their evaluation , the company 's ceo and cfo have concluded that the company 's disclosure controls and procedures ( as defined in rules 13a-15 ( e ) and 15d-15 ( e ) under the exchange act ) were effective as of december 31 , 2018. annual report on internal control over financial reporting management is responsible for establishing and maintaining adequate internal control over financial reporting ( “ icfr ” ) as defined in rules 13a-15 ( f ) and 15d-15 ( f ) under the exchange act . our icfr is a process designed by , or under the supervision of , our ceo and our cfo to provide reasonable assurance regarding the reliability of financial reporting and the preparation of our consolidated financial statements for external purposes in accordance with generally accepted accounting principles ( “ gaap ” ) in the united states of america . management , with the participation of our ceo and cfo , conducted an evaluation of the effectiveness of our icfr based on the framework established in internal control—integrated framework ( 2013 ) issued by the committee of sponsoring organizations of the treadway commission . based upon that evaluation , management has concluded that the company 's internal control over financial reporting was effective as of december 31 , 2018 . - 30 - the effectiveness of the company 's internal control over financial reporting has also been audited by deloitte & touche llp , the company 's independent registered public accounting firm , as stated in their report included below . changes in internal control over financial reporting there have been no changes in the company 's internal control over financial reporting that occurred during the quarter ended december 31 , 2018 that have materially affected , or are reasonably likely to materially affect , the company 's internal control over financial reporting . inherent limitations control systems , no matter how well designed and operated , can provide only reasonable , not absolute , assurance that the control systems ' objectives are being met . further , the design of any control systems must reflect the fact that there are resource constraints , and the benefits of all controls must be considered relative to their costs . due to the inherent limitations in all control systems , no evaluation of controls can provide absolute assurance that all control issues and instances of fraud , if any , within the company have been detected . these inherent limitations include the realities that judgments in decision making can be faulty and that breakdowns can occur because of simple errors or mistakes . control systems can also be circumvented by the individual acts of some persons , by collusion of two or more people , or by management override of the controls . the design of any system of controls is based in part on certain assumptions about the likelihood of future events , and there can be no assurance that any design will succeed in achieving its stated goals under all

liquidity and capital resources the company 's cash balance of $ 140.7 million , which includes cash , cash equivalents , and restricted cash , increased $ 20.5 million for the twelve months ended december 31 , 2018 , compared to a decrease of $ 221.1 million for the comparable period of 2017. the increase in cash at december 31 , 2018 as compared to december 31 , 2017 was primarily due to decreased purchases of restricted investments . net cash provided by operating activities in 2018 amounted to $ 69.8 million , compared to net cash provided of $ 112.9 million for the comparable period of 2017. in 2018 , cash flow from operating activities was primarily provided by net income of $ 38.1 million and increased workers ' compensation claims liabilities of $ 49.6 million , partially offset by decreased accrued payroll , payroll taxes and related benefits of $ 21.9 million and increased trade accounts receivable of $ 14.9 million . net cash used in investing activities totaled $ 39.3 million in 2018 , compared to net cashed used of $ 325.0 million for the comparable period of 2017. in 2018 , cash used in investing activities consisted primarily of purchases of investments and restricted investments of $ 110.7 million , partially offset by proceeds from sales and maturities of investments and restricted investments of $ 76.5 million . net cash used in financing activities in 2018 was $ 9.9 million compared to net cash used of $ 9.0 million for the comparable period of 2017. in 2018 , cash was primarily used for dividend payments of $ 7.3 million and common stock repurchased on vesting of restricted stock units of $ 3.0 million . - 27 - the states of california , maryland , oregon , washington , colorado and delaware required us to maintain specified financial instruments totaling $ 85.2 million and $ 96.8 million at december 31 , 2018 and 2017 , respectively , to cover potential workers ' compensation claims losses related to the company 's current and former status as a self-insured employer .


 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 the company 's cash balance of $ 140.7 million , which includes cash , cash equivalents , and restricted cash , increased $ 20.5 million for the twelve months ended december 31 , 2018 , compared to a decrease of $ 221.1 million for the comparable period of 2017. the increase in cash at december 31 , 2018 as compared to december 31 , 2017 was primarily due to decreased purchases of restricted investments . net cash provided by operating activities in 2018 amounted to $ 69.8 million , compared to net cash provided of $ 112.9 million for the comparable period of 2017. in 2018 , cash flow from operating activities was primarily provided by net income of $ 38.1 million and increased workers ' compensation claims liabilities of $ 49.6 million , partially offset by decreased accrued payroll , payroll taxes and related benefits of $ 21.9 million and increased trade accounts receivable of $ 14.9 million . net cash used in investing activities totaled $ 39.3 million in 2018 , compared to net cashed used of $ 325.0 million for the comparable period of 2017. in 2018 , cash used in investing activities consisted primarily of purchases of investments and restricted investments of $ 110.7 million , partially offset by proceeds from sales and maturities of investments and restricted investments of $ 76.5 million . net cash used in financing activities in 2018 was $ 9.9 million compared to net cash used of $ 9.0 million for the comparable period of 2017. in 2018 , cash was primarily used for dividend payments of $ 7.3 million and common stock repurchased on vesting of restricted stock units of $ 3.0 million . - 27 - the states of california , maryland , oregon , washington , colorado and delaware required us to maintain specified financial instruments totaling $ 85.2 million and $ 96.8 million at december 31 , 2018 and 2017 , respectively , to cover potential workers ' compensation claims losses related to the company 's current and former status as a self-insured employer .
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 Suspicious Activity Report : - 21 - depreciation and amortization represent depreciation of property and equipment , leasehold improvements and capitalized software costs . property , equipment and software are depreciated using t he straight-line method over their estimated useful lives , which range from 3 to 39 years . leasehold improvements are amortized using the straight-line method over the shorter of the lease term or estimated useful life . critical accounting policies and estimates we have identified the following accounting estimate as critical to our business and the understanding of our results of operations . for a detailed discussion of the application of this and other accounting policies , see “ note 1 - summary of operations and significant accounting policies ” to the consolidated financial statements incorporated into item 8 of part ii of this report . the preparation of this annual report on form 10-k requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements , and the reported amounts of revenue and expenses during the reporting period . management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances , the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources . actual results may differ from these estimates . workers ' compensation reserves we recognize our liability for the ultimate payment of incurred claims and claims adjustment expenses by establishing a reserve which represents our estimates of future amounts necessary to pay claims and related expenses with respect to workplace injuries that have occurred . when a claim involving a probable loss is reported , our independent third-party administrator for workers ' compensation claims ( “ tpa ” ) establishes a case reserve for the estimated amount of ultimate loss . the estimate reflects a judgment based on established case reserving practices and the experience and knowledge of the tpa regarding the nature and expected amount of the claim , as well as the estimated expenses of settling the claim , including legal and other fees and expenses of claims administration . the adequacy of such case reserves in part depends on the professional judgment of the tpa to properly and comprehensively evaluate the economic consequences of each claim . our reserves include an additional component for potential future increases in the cost to finally resolve open injury claims and claims incurred in prior periods but not reported ( together , `` ibnr `` ) based on actuarial estimates provided by the company 's independent actuary . ibnr reserves , unlike specific case reserves , do not apply to a specific claim but rather apply to the entire population of claims arising from a specific time period . ibnr primarily covers costs relating to : future claim payments in excess of case reserves on recorded open claims ; additional claim payments on closed claims ; and claims that have occurred but have not yet been reported to us . the process of estimating unpaid claims and claims adjustment expense involves a high degree of judgment and is affected by both internal and external events , including changes in claims handling practices , modifications in reserve estimation procedures , changes in individuals involved in the reserve estimation process , inflation , trends in the litigation and settlement of pending claims , and legislative changes . our estimates are based on informed judgment , derived from individual experiences and expertise applied to multiple sets of data and analyses . we consider significant facts and circumstances known both at the time that loss reserves are initially established and as new facts and circumstances become known . due to the inherent uncertainty underlying loss reserve estimates , the expenses incurred through final resolution of our liability for our workers ' compensation claims will likely vary from the related loss reserves at the reporting date . therefore , as specific claims are paid out in the future , actual paid losses may be materially different from our current loss reserves . - 22 - a basic premise in most actu arial analyses is that historical data and past patterns demonstrated in the incurred and paid historical data form a reasonable basis upon which to project future outcomes , absent a material change . significant structural changes to the available data can materially impact the reserve estimation process . to the extent a material change affecting the ultimate claim liability becomes known , such change is quantified to the extent possible through an analysis of internal company data and , if available and whe n appropriate , external data . actuaries exercise a considerable degree of judgment in the evaluation of these factors and the need for such actuarial judgment is more pronounced when faced with material uncertainties . we believe that the amounts recorded for our estimated liabilities for workers ' compensation claims , which are based on informed judgment , analysis of data , actuarial estimates , and analysis of other trends associated with the company 's historical universe of claims data , are reasonable . nevertheless , adjustments to such estimates will be required in future periods if the development of claim costs varies materially from our estimates and such future adjustments may be material to our results of operations . recent accounting pronouncements for a discussion of recent accounting pronouncements and their potential effect on the company 's results of operations and financial condition , see “ note 1 - summary of operations and significant accounting policies ” to the consolidated financial statements incorporated into item 8 of part ii of this report . story_separator_special_tag contractual obligations the company 's contractual obligations as of december 31 , 2018 are summarized below : replace_table_token_9_th inflation inflation generally has not been a significant factor in the company 's operations during the periods discussed above . the company has taken into account the impact of escalating medical and other costs in establishing reserves for future workers ' compensation claims payments . - 29 - item 7a . quantitative and qualitat ive disclosures about market risk the company 's exposure to market risk for changes in interest rates primarily relates to its investment portfolio and its outstanding borrowings on its line of credit and long-term debt . as of december 31 , 2018 , the company 's investments consisted principally of approximately $ 181.8 million in corporate bonds , $ 87.9 million in mortgage backed securities , $ 45.2 million in u.s. treasuries , $ 44.7 million in u.s. government agency securities , $ 4.7 million in supranational , $ 1.1 million in mutual funds , and $ 0.4 million in money market funds . the company 's outstanding debt totaled approximately $ 4.2 million at december 31 , 2018. based on the company 's overall interest exposure at december 31 , 2018 , a 50 basis point increase in market interest rates would have a $ 5.6 million effect on the fair value of the company 's investment portfolio . a 50 basis point increase would have an immaterial effect on the company 's outstanding borrowings because of the relative size of the outstanding borrowings . item 8. financial statements and supplementary data the consolidated financial statements and notes thereto required by this item begin on page f-1 of this report , as listed in item 15. item 9. changes in and disagreements with accountants on accounting and financial disclosure none . item 9a . controls and procedures evaluation of disclosure controls and procedures we maintain “ disclosure controls and procedures ” that are designed with the objective of providing reasonable assurance that information required to be disclosed in the reports we file or submit under the securities exchange act of 1934 , as amended ( the “ exchange act ” ) , is recorded , processed , summarized , and reported within the time periods specified in the sec 's rules and forms , and that such information is accumulated and communicated to our management , including our chief executive officer ( “ ceo ” ) and chief financial officer ( “ cfo ” ) , as appropriate , to allow timely decisions regarding required disclosure . in designing and evaluating our disclosure controls and procedures , our management recognizes that any controls and procedures , no matter how well designed and operated , can provide only reasonable assurance of achieving the desired control objectives , and our management is required to apply their judgment in evaluating the cost-benefit relationship of possible controls and procedures . based on their evaluation , the company 's ceo and cfo have concluded that the company 's disclosure controls and procedures ( as defined in rules 13a-15 ( e ) and 15d-15 ( e ) under the exchange act ) were effective as of december 31 , 2018. annual report on internal control over financial reporting management is responsible for establishing and maintaining adequate internal control over financial reporting ( “ icfr ” ) as defined in rules 13a-15 ( f ) and 15d-15 ( f ) under the exchange act . our icfr is a process designed by , or under the supervision of , our ceo and our cfo to provide reasonable assurance regarding the reliability of financial reporting and the preparation of our consolidated financial statements for external purposes in accordance with generally accepted accounting principles ( “ gaap ” ) in the united states of america . management , with the participation of our ceo and cfo , conducted an evaluation of the effectiveness of our icfr based on the framework established in internal control—integrated framework ( 2013 ) issued by the committee of sponsoring organizations of the treadway commission . based upon that evaluation , management has concluded that the company 's internal control over financial reporting was effective as of december 31 , 2018 . - 30 - the effectiveness of the company 's internal control over financial reporting has also been audited by deloitte & touche llp , the company 's independent registered public accounting firm , as stated in their report included below . changes in internal control over financial reporting there have been no changes in the company 's internal control over financial reporting that occurred during the quarter ended december 31 , 2018 that have materially affected , or are reasonably likely to materially affect , the company 's internal control over financial reporting . inherent limitations control systems , no matter how well designed and operated , can provide only reasonable , not absolute , assurance that the control systems ' objectives are being met . further , the design of any control systems must reflect the fact that there are resource constraints , and the benefits of all controls must be considered relative to their costs . due to the inherent limitations in all control systems , no evaluation of controls can provide absolute assurance that all control issues and instances of fraud , if any , within the company have been detected . these inherent limitations include the realities that judgments in decision making can be faulty and that breakdowns can occur because of simple errors or mistakes . control systems can also be circumvented by the individual acts of some persons , by collusion of two or more people , or by management override of the controls . the design of any system of controls is based in part on certain assumptions about the likelihood of future events , and there can be no assurance that any design will succeed in achieving its stated goals under all

