additionally , the positive lending environment has sustained continued new development within our specialty services space . residential —continuing revenue growth of the company 's residential construction business is directly related to the growth of new home starts in its key markets . the company 's core customer base is primarily made up of leading national home builders as well as regional and custom home builders . the company has continued its expansion of the residential business into the houston market and surrounding areas . 23 backlog at december 31 , 2019 , our backlog of construction projects , made up of our heavy civil and specialty services segments , was $ 1.1 billion , as compared to $ 850.7 million at december 31 , 2018 . the contracts in backlog are typically completed in 6 to 36 months . contracts in which we are the apparent low bidder for projects ( “ unsigned low-bid awards ” ) are excluded from backlog until the contract is executed by our customer . unsigned low-bid awards were $ 273.5 million at december 31 , 2019 and $ 292.7 million at the end of 2018 . the combination of our backlog and unsigned low-bid awards , which we refer to as “ combined backlog ” totaled $ 1.3 billion and $ 1.1 billion as of december 31 , 2019 and 2018 , respectively . backlog includes $ 161.4 million and $ 33.6 million attributable to our share of estimated revenues related to joint ventures where we are a noncontrolling joint venture partner at december 31 , 2019 and 2018 , respectively . we anticipate that approximately 70 % of our backlog will be recognized as revenues during 2020 , with substantially all remaining recognized in the twelve months following . contracts-in-progress which were not substantially complete totaled approximately 200 and 150 at december 31 , 2019 and 2018 , respectively . these contracts are of various sizes , of different expected profitability and in various stages of completion . the nearer a contract progresses toward completion , the more visibility we have in refining our estimate of total revenues ( including incentives , delay penalties and change orders ) , costs and gross profit . thus , gross profit as a percent of revenues can increase or decrease from comparable and sequential quarters due to variations among contracts and depending upon the stage of completion of contracts . we anticipate that our markets will continue to improve , driven by the conditions discussed in item 1 . “ business . ” furthermore , we believe that the company is well established in our particular markets and has the management depth and experience which gives us the ability to perform a broad range of work that will allow us to succeed in current market conditions and to continue to compete successfully for projects as they become available at acceptable profit margin levels . backlog and gross margin : replace_table_token_2_th our total margin in backlog has increased approximately 300 basis points , from 8.5 % at december 31 , 2018 to 11.5 % at december 31 , 2019 , primarily due to the $ 159 million of plateau backlog acquired at the acquisition closing date . our combined backlog margin increased from 8.9 % at december 31 , 2018 to 11.0 % at december 31 , 2019 . the increases noted above are primarily the result of the plateau acquisition , improving market conditions , and actions that we have taken to improve bid discipline . 24 results of operations consolidated results summary— for 2019 , the company had operating income of $ 37.8 million , income before income taxes of $ 14.5 million , net income attributable to sterling common stockholders of $ 39.9 million and net income per diluted share attributable to sterling common stockholders of $ 1.47 . consolidated financial highlights for 2019 as compared to 2018 are as follows : replace_table_token_3_th nm – not meaningful . revenues— revenues increase d $ 88.6 million , or 8.5 % in 2019 compared to the prior year . the increase is primarily attributable to the inclusion of three months of revenue totaling $ 84.6 million from the acquired plateau operations in 2019 . gross profit— gross profit decrease d $ 2.5 million , or 2.3 % , in 2019 compared to the prior year . the company 's gross margin as a percent of revenue decreased to 9.6 % in 2019 , as compared to 10.6 % in the prior year . in december 2019 , sterling was able to come to an interim agreement related to a 2014 project involving the construction of three separate bridges in texas that had suffered from significant schedule delays and cost overruns due to major owner design flaws . this agreement enabled sterling to recover approximately $ 17 million in costs to date related to these delays and defined a better dispute resolution process along with agreed upon rates for potential future delays . as part of this agreement , sterling agreed to work on all three bridges simultaneously ( versus doing one at a time ) to accelerate the final completion schedule . this revised schedule has significantly increased the amount of labor , equipment and infrastructure required to complete the project under the new terms of the agreement and resulted in a reduction of gross profit in the quarter of $ 10.2 million , or $ 0.36 per diluted share . the decrease in gross margin during 2019 , when compared to the prior year , was driven by the aforementioned $ 10.2 million charge and a lower margin revenue mix due to the completion of two large design-build projects at the end of 2018 . the company expects the margin mix to improve in 2020 with the ramp up of several large design-build projects which are now in backlog . story_separator_special_tag we have pledged all proceeds and other rights under our construction contracts to our bond surety company . events that affect the insurance and bonding markets may result in bonding becoming more difficult to obtain in the future , or being available only at a significantly greater cost . to date , we have not encountered difficulties or material cost increases in obtaining new surety bonds . capital expenditures — capital equipment is acquired as needed by increased levels of production and to replace retiring equipment . capital expenditures incurred in 2019 were $ 15.4 million . management expects capital expenditures in 2020 to be in the range of $ 22 to $ 27 million due to the full year impact of the plateau acquisition ; however , the award of a project requiring significant purchases of equipment or other factors could result in increased expenditures . inflation — inflation generally has not had a material impact on our financial results ; however , from time to time increases in oil , fuel , and steel prices have affected our cost of operations . anticipated cost increases and reductions are considered in our bids to customers on proposed new construction projects . where we are the successful bidder on a heavy civil or specialty services project , we execute purchase orders with material suppliers and contracts with subcontractors covering the prices of most materials and services , other than oil and fuel products , thereby mitigating future price increases and supply disruptions . these purchase orders and contracts do not contain quantity guarantees and we have no obligation for materials and services beyond those required to complete the contracts with our customers . there can be no assurance that increases in prices of oil and fuel used in our business will be adequately covered by the estimated escalation we have included in our bids and there can be no assurance that all of our vendors will fulfill their pricing and supply 31 commitments under their purchase orders and contracts with the company . we adjust our total estimated costs on our projects when we believe it is probable that we will have cost increases which will not be recovered from customers , vendors or re-engineering . inflation affects our residential projects minimally , as the time from starting construction to finishing is typically less than one month . off-balance sheet arrangements and joint ventures we participate in various construction joint venture partnerships in order to share expertise , risk and resources for certain highly complex projects . the joint venture 's contract with the project owner typically requires joint and several liability among the joint venture partners . although our agreements with our joint venture partners provide that each party will assume and fund its share of any losses resulting from a project , if one of our partners was unable to pay its share , we would be fully liable for such share under our contract with the project owner . circumstances that could lead to a loss under these guarantee arrangements include a partner 's inability to contribute additional funds to the venture in the event that the project incurred a loss or additional costs that we could incur should the partner fail to provide the services and resources toward project completion that had been committed to in the joint venture agreement . see item 1a “ risk factors . ” at december 31 , 2019 , there was approximately $ 392.0 million of construction work to be completed on unconsolidated construction joint venture contracts , of which $ 161.4 million represented our proportionate share . due to the joint and several liability under our joint venture arrangements , if one of our joint venture partners fails to perform , we and the remaining joint venture partners would be responsible for completion of the outstanding work . as of december 31 , 2019 , we are not aware of any situation that would require us to fulfill responsibilities of our joint venture partners pursuant to the joint and several liability under our contracts . new accounting standards see the applicable section of note 2 - basis of presentation and significant accounting policies for a discussion of new accounting standards . critical accounting estimates the discussion and analysis of the financial condition and results of operations are based on the company 's consolidated financial statements , which have been prepared in accordance with u.s. gaap . the preparation of these consolidated financial statements requires the company to make estimates and judgments that affect the reported amounts of assets , liabilities , revenue and expenses and related disclosures of contingent assets and liabilities . the company continually evaluates its estimates based on historical experience and various other assumptions that the company believes to be reasonable under the circumstances . actual results may differ from these estimates under different assumptions or conditions . the company believes the following critical accounting policies involve more significant judgments and estimates used in the preparation of the consolidated financial statements . revenue recognition performance obligations satisfied over time —revenue for contracts that satisfy the criteria for over time recognition is recognized as the work progresses . the company measures transfer of control of the performance obligation utilizing the cost-to-cost measure of progress , with cost of revenue including direct costs , such as materials and labor , and indirect costs that are attributable to contract activity . under the cost-to-cost approach , the use of estimated costs to complete each performance obligation is a significant variable in the process of determining recognized revenue and is a significant factor in the accounting for such performance obligations . significant estimates that impact the cost to complete each performance obligation are : materials , components , equipment , labor and subcontracts ; labor productivity ; schedule durations , including subcontractor or supplier progress ; contract disputes , including claims ; achievement of contractual performance requirements ; and contingency

cash and cash equivalents $ 45,733 $ 94,095 working capital ( current assets minus current liabilities ) $ 64,017 $ 123,442 operating activities— during 2019 , net cash provided by operating activities was $ 41.1 million compared to net cash provided of $ 39.5 million in the prior year . cash flows provided by operating activities were driven by net income , adjusted for various non-cash items and changes in accounts receivable , net contracts in progress and accounts payable balances ( collectively , “ contract capital ” ) , as discussed below . 27 cash— cash at december 31 , 2019 , was $ 45.7 million , and includes the following components : replace_table_token_6_th the decrease in total cash is primarily due to the company 's acquisition of plateau ( including the associated repayment of the oaktree facility ) . the decrease in consolidated 50 % owned subsidiaries and construction joint venture cash levels were driven by the substantial completion of two large construction joint venture projects in the prior year . working and contract capital— sterling 's working capital decreased $ 59.4 million to $ 64.0 million at december 31 , 2019 from $ 123.4 million at december 31 , 2018 , primarily due to the plateau acquisition . the need for working capital for our business varies due to fluctuations in operating activities and investments in our contract capital . the changes in components of contract capital at december 31 , 2019 and 2018 and variances were as follows : replace_table_token_7_th during 2019 , the change in contract capital had an impact of $ 2.8 million . fluctuations in the contract capital balance and its components are not unusual and are impacted by the size of projects and changing type and mix of projects in backlog . the company 's contract capital is particularly impacted by seasonality , the timing of new awards , and related payments of performing work and the contract billings to the customer as projects are completed . contract capital is also impacted at period-end by the timing of accounts receivable collections and accounts payable payments for projects .


 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 and cash equivalents $ 45,733 $ 94,095 working capital ( current assets minus current liabilities ) $ 64,017 $ 123,442 operating activities— during 2019 , net cash provided by operating activities was $ 41.1 million compared to net cash provided of $ 39.5 million in the prior year . cash flows provided by operating activities were driven by net income , adjusted for various non-cash items and changes in accounts receivable , net contracts in progress and accounts payable balances ( collectively , “ contract capital ” ) , as discussed below . 27 cash— cash at december 31 , 2019 , was $ 45.7 million , and includes the following components : replace_table_token_6_th the decrease in total cash is primarily due to the company 's acquisition of plateau ( including the associated repayment of the oaktree facility ) . the decrease in consolidated 50 % owned subsidiaries and construction joint venture cash levels were driven by the substantial completion of two large construction joint venture projects in the prior year . working and contract capital— sterling 's working capital decreased $ 59.4 million to $ 64.0 million at december 31 , 2019 from $ 123.4 million at december 31 , 2018 , primarily due to the plateau acquisition . the need for working capital for our business varies due to fluctuations in operating activities and investments in our contract capital . the changes in components of contract capital at december 31 , 2019 and 2018 and variances were as follows : replace_table_token_7_th during 2019 , the change in contract capital had an impact of $ 2.8 million . fluctuations in the contract capital balance and its components are not unusual and are impacted by the size of projects and changing type and mix of projects in backlog . the company 's contract capital is particularly impacted by seasonality , the timing of new awards , and related payments of performing work and the contract billings to the customer as projects are completed . contract capital is also impacted at period-end by the timing of accounts receivable collections and accounts payable payments for projects .
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 Suspicious Activity Report : additionally , the positive lending environment has sustained continued new development within our specialty services space . residential —continuing revenue growth of the company 's residential construction business is directly related to the growth of new home starts in its key markets . the company 's core customer base is primarily made up of leading national home builders as well as regional and custom home builders . the company has continued its expansion of the residential business into the houston market and surrounding areas . 23 backlog at december 31 , 2019 , our backlog of construction projects , made up of our heavy civil and specialty services segments , was $ 1.1 billion , as compared to $ 850.7 million at december 31 , 2018 . the contracts in backlog are typically completed in 6 to 36 months . contracts in which we are the apparent low bidder for projects ( “ unsigned low-bid awards ” ) are excluded from backlog until the contract is executed by our customer . unsigned low-bid awards were $ 273.5 million at december 31 , 2019 and $ 292.7 million at the end of 2018 . the combination of our backlog and unsigned low-bid awards , which we refer to as “ combined backlog ” totaled $ 1.3 billion and $ 1.1 billion as of december 31 , 2019 and 2018 , respectively . backlog includes $ 161.4 million and $ 33.6 million attributable to our share of estimated revenues related to joint ventures where we are a noncontrolling joint venture partner at december 31 , 2019 and 2018 , respectively . we anticipate that approximately 70 % of our backlog will be recognized as revenues during 2020 , with substantially all remaining recognized in the twelve months following . contracts-in-progress which were not substantially complete totaled approximately 200 and 150 at december 31 , 2019 and 2018 , respectively . these contracts are of various sizes , of different expected profitability and in various stages of completion . the nearer a contract progresses toward completion , the more visibility we have in refining our estimate of total revenues ( including incentives , delay penalties and change orders ) , costs and gross profit . thus , gross profit as a percent of revenues can increase or decrease from comparable and sequential quarters due to variations among contracts and depending upon the stage of completion of contracts . we anticipate that our markets will continue to improve , driven by the conditions discussed in item 1 . “ business . ” furthermore , we believe that the company is well established in our particular markets and has the management depth and experience which gives us the ability to perform a broad range of work that will allow us to succeed in current market conditions and to continue to compete successfully for projects as they become available at acceptable profit margin levels . backlog and gross margin : replace_table_token_2_th our total margin in backlog has increased approximately 300 basis points , from 8.5 % at december 31 , 2018 to 11.5 % at december 31 , 2019 , primarily due to the $ 159 million of plateau backlog acquired at the acquisition closing date . our combined backlog margin increased from 8.9 % at december 31 , 2018 to 11.0 % at december 31 , 2019 . the increases noted above are primarily the result of the plateau acquisition , improving market conditions , and actions that we have taken to improve bid discipline . 24 results of operations consolidated results summary— for 2019 , the company had operating income of $ 37.8 million , income before income taxes of $ 14.5 million , net income attributable to sterling common stockholders of $ 39.9 million and net income per diluted share attributable to sterling common stockholders of $ 1.47 . consolidated financial highlights for 2019 as compared to 2018 are as follows : replace_table_token_3_th nm – not meaningful . revenues— revenues increase d $ 88.6 million , or 8.5 % in 2019 compared to the prior year . the increase is primarily attributable to the inclusion of three months of revenue totaling $ 84.6 million from the acquired plateau operations in 2019 . gross profit— gross profit decrease d $ 2.5 million , or 2.3 % , in 2019 compared to the prior year . the company 's gross margin as a percent of revenue decreased to 9.6 % in 2019 , as compared to 10.6 % in the prior year . in december 2019 , sterling was able to come to an interim agreement related to a 2014 project involving the construction of three separate bridges in texas that had suffered from significant schedule delays and cost overruns due to major owner design flaws . this agreement enabled sterling to recover approximately $ 17 million in costs to date related to these delays and defined a better dispute resolution process along with agreed upon rates for potential future delays . as part of this agreement , sterling agreed to work on all three bridges simultaneously ( versus doing one at a time ) to accelerate the final completion schedule . this revised schedule has significantly increased the amount of labor , equipment and infrastructure required to complete the project under the new terms of the agreement and resulted in a reduction of gross profit in the quarter of $ 10.2 million , or $ 0.36 per diluted share . the decrease in gross margin during 2019 , when compared to the prior year , was driven by the aforementioned $ 10.2 million charge and a lower margin revenue mix due to the completion of two large design-build projects at the end of 2018 . the company expects the margin mix to improve in 2020 with the ramp up of several large design-build projects which are now in backlog . story_separator_special_tag we have pledged all proceeds and other rights under our construction contracts to our bond surety company . events that affect the insurance and bonding markets may result in bonding becoming more difficult to obtain in the future , or being available only at a significantly greater cost . to date , we have not encountered difficulties or material cost increases in obtaining new surety bonds . capital expenditures — capital equipment is acquired as needed by increased levels of production and to replace retiring equipment . capital expenditures incurred in 2019 were $ 15.4 million . management expects capital expenditures in 2020 to be in the range of $ 22 to $ 27 million due to the full year impact of the plateau acquisition ; however , the award of a project requiring significant purchases of equipment or other factors could result in increased expenditures . inflation — inflation generally has not had a material impact on our financial results ; however , from time to time increases in oil , fuel , and steel prices have affected our cost of operations . anticipated cost increases and reductions are considered in our bids to customers on proposed new construction projects . where we are the successful bidder on a heavy civil or specialty services project , we execute purchase orders with material suppliers and contracts with subcontractors covering the prices of most materials and services , other than oil and fuel products , thereby mitigating future price increases and supply disruptions . these purchase orders and contracts do not contain quantity guarantees and we have no obligation for materials and services beyond those required to complete the contracts with our customers . there can be no assurance that increases in prices of oil and fuel used in our business will be adequately covered by the estimated escalation we have included in our bids and there can be no assurance that all of our vendors will fulfill their pricing and supply 31 commitments under their purchase orders and contracts with the company . we adjust our total estimated costs on our projects when we believe it is probable that we will have cost increases which will not be recovered from customers , vendors or re-engineering . inflation affects our residential projects minimally , as the time from starting construction to finishing is typically less than one month . off-balance sheet arrangements and joint ventures we participate in various construction joint venture partnerships in order to share expertise , risk and resources for certain highly complex projects . the joint venture 's contract with the project owner typically requires joint and several liability among the joint venture partners . although our agreements with our joint venture partners provide that each party will assume and fund its share of any losses resulting from a project , if one of our partners was unable to pay its share , we would be fully liable for such share under our contract with the project owner . circumstances that could lead to a loss under these guarantee arrangements include a partner 's inability to contribute additional funds to the venture in the event that the project incurred a loss or additional costs that we could incur should the partner fail to provide the services and resources toward project completion that had been committed to in the joint venture agreement . see item 1a “ risk factors . ” at december 31 , 2019 , there was approximately $ 392.0 million of construction work to be completed on unconsolidated construction joint venture contracts , of which $ 161.4 million represented our proportionate share . due to the joint and several liability under our joint venture arrangements , if one of our joint venture partners fails to perform , we and the remaining joint venture partners would be responsible for completion of the outstanding work . as of december 31 , 2019 , we are not aware of any situation that would require us to fulfill responsibilities of our joint venture partners pursuant to the joint and several liability under our contracts . new accounting standards see the applicable section of note 2 - basis of presentation and significant accounting policies for a discussion of new accounting standards . critical accounting estimates the discussion and analysis of the financial condition and results of operations are based on the company 's consolidated financial statements , which have been prepared in accordance with u.s. gaap . the preparation of these consolidated financial statements requires the company to make estimates and judgments that affect the reported amounts of assets , liabilities , revenue and expenses and related disclosures of contingent assets and liabilities . the company continually evaluates its estimates based on historical experience and various other assumptions that the company believes to be reasonable under the circumstances . actual results may differ from these estimates under different assumptions or conditions . the company believes the following critical accounting policies involve more significant judgments and estimates used in the preparation of the consolidated financial statements . revenue recognition performance obligations satisfied over time —revenue for contracts that satisfy the criteria for over time recognition is recognized as the work progresses . the company measures transfer of control of the performance obligation utilizing the cost-to-cost measure of progress , with cost of revenue including direct costs , such as materials and labor , and indirect costs that are attributable to contract activity . under the cost-to-cost approach , the use of estimated costs to complete each performance obligation is a significant variable in the process of determining recognized revenue and is a significant factor in the accounting for such performance obligations . significant estimates that impact the cost to complete each performance obligation are : materials , components , equipment , labor and subcontracts ; labor productivity ; schedule durations , including subcontractor or supplier progress ; contract disputes , including claims ; achievement of contractual performance requirements ; and contingency

