given the fixed price nature of much of our project work , if our initial estimate of project costs is wrong or we incur cost overruns that can not be recovered in change orders , we can experience reduced profits or even significant losses on fixed price project work . we also perform some project work on a cost‑plus or a time and materials basis , under which we are paid our costs incurred plus an agreed‑upon profit margin , and such projects are sometimes subject to a guaranteed maximum cost . these margins are frequently less than fixed‑price contract margins because there is less risk of unrecoverable cost overruns in cost‑plus or time and materials work . as of december 31 , 2018 , we had 5,208 projects in process . our average project takes six to nine months to complete , with an average contract price of approximately $ 597,000. our projects generally require working capital funding of equipment and labor costs . customer payments on periodic billings generally do not recover these costs until late in the job . our average project duration together with typical retention terms as discussed above generally allow us to complete the realization of revenue and earnings in cash within one year . we have what we believe is a well‑diversified distribution of revenue across end‑use sectors that we believe reduces our exposure to negative developments in any given sector . because of the integral nature of hvac and related controls systems to most buildings , we have the legal right in almost all cases to attach liens to buildings or related funding sources when we have not been fully paid for installing systems , except with respect to some government buildings . the service work that we do , which is discussed further below , usually does not give rise to lien rights . we also perform larger projects . taken together , projects with contract prices of $ 1 million or more totaled $ 2.51 billion of aggregate contract value as of december 31 , 2018 , or approximately 80 % , out of a total contract value for all projects in progress of $ 3.11 billion . generally , projects closer in size to $ 1 million will be completed in one year or less . it is unusual for us to work on a project that exceeds two years in length . a stratification of projects in progress as of december 31 , 2018 , by contract price , is as follows : replace_table_token_6_th 25 in addition to project work , approximately 16.0 % of our revenue represents maintenance and repair service on already installed hvac and controls systems . this kind of work usually takes from a few hours to a few days to perform . prices to the customer are based on the equipment and materials used in the service as well as technician labor time . we usually bill the customer for service work when it is complete , typically with payment terms of up to thirty days . we also provide maintenance and repair service under ongoing contracts . under these contracts , we are paid regular monthly or quarterly amounts and provide specified service based on customer requirements . these agreements typically are for one or more years and frequently contain thirty‑ to sixty‑day cancellation notice periods . a relatively small portion of our revenue comes from national and regional account customers . these customers typically have multiple sites , and contract with us to perform maintenance and repair service . these contracts may also provide for us to perform new or replacement systems installation . we operate a national call center to dispatch technicians to sites requiring service . we perform the majority of this work with our own employees , with the balance being subcontracted to third parties that meet our performance qualifications . profile and management of our operations we manage our 36 operating units based on a variety of factors . financial measures we emphasize include profitability , and use of capital as indicated by cash flow and by other measures of working capital principally involving project cost , billings and receivables . we also monitor selling , general , administrative and indirect project support expense , backlog , workforce size and mix , growth in revenue and profits , variation of actual project cost from original estimate , and overall financial performance in comparison to budget and updated forecasts . operational factors we emphasize include project selection , estimating , pricing , management and execution practices , labor utilization , safety , training , and the make‑up of both existing backlog as well as new business being pursued , in terms of project size , technical application and facility type , end‑use customers and industries , and location of the work . most of our operations compete on a local or regional basis . attracting and retaining effective operating unit managers is an important factor in our business , particularly in view of the relative uniqueness of each market and operation , the importance of relationships with customers and other market participants such as architects and consulting engineers , and the high degree of competition and low barriers to entry in most of our markets . accordingly , we devote considerable attention to operating unit management quality , stability , and contingency planning , including related considerations of compensation , and non‑competition protection where applicable . economic and industry factors as a mechanical and building controls services provider , we operate in the broader nonresidential construction services industry and are affected by trends in this sector . while we do not have operations in all major cities of the united states , we believe our national presence is sufficiently large that we experience trends in demand for and pricing of our services that are consistent with trends in the national nonresidential construction sector . story_separator_special_tag if we conclude otherwise , then we perform the first step of a two‑step impairment test by calculating the fair value of the reporting unit and comparing the fair value with the carrying value of the reporting unit . we estimate the fair value of the reporting unit based on a market approach and an income approach , which utilizes discounted future cash flows . assumptions critical to the fair value estimates under the discounted cash flow model include discount rates , cash flow projections , projected long‑term growth rates and the determination of terminal values . the market approach utilized market multiples of invested capital from comparable publicly traded companies ( “ public company approach ” ) . the market multiples from invested capital include revenue , book equity plus debt and earnings before interest , provision for income taxes , depreciation and amortization ( “ ebitda ” ) . there are significant inherent uncertainties and management judgment involved in estimating the fair value of each reporting unit . while we believe we have made reasonable estimates and assumptions to estimate the fair value of our reporting units , it is possible that a material change could occur . if actual results are not consistent with our current estimates and assumptions , or the current economic outlook worsens , goodwill impairment charges may be recorded in future periods . we amortize identifiable intangible assets with finite lives over their useful lives . changes in strategy and or market condition , may result in adjustments to recorded intangible asset balances or their useful lives . results of operations ( in thousands ) : replace_table_token_7_th 2018 compared to 2017 we had 36 operating locations as of december 31 , 2017. in the third quarter of 2018 , we completed one acquisition of a company that reports as a separate operating location in indiana ( the “ indiana acquisition ” ) . furthermore , in the fourth quarter of 2018 , we combined two operating locations into one . as of december 31 , 2018 , we had 36 operating locations . acquisitions are included in our results of operations from the respective acquisition date . the same‑store comparison from 2018 to 2017 , as described below , excludes six months of results for the indiana acquisition , which was acquired in july 2018 , as well as the first three months of 2018 for bch , which was acquired in april 2017. an operating location is included in the same‑store comparison on the first day it has comparable prior year operating data , except for immaterial acquisitions that were absorbed and integrated , or “ tucked-in , ” with existing operations . 30 revenue —revenue increased $ 395.0 million , or 22.1 % to $ 2.18 billion in 2018 compared to 2017. the increase included a 5.1 % increase related to the indiana and bch acquisitions and a 17.0 % increase in revenue related to same‑store activity . the same‑store revenue increase was broad-based , including an increase in activity at our north carolina operation ( $ 123.6 million ) , one of our virginia operations ( $ 25.4 million ) and our wisconsin operation ( $ 23.0 million ) . backlog reflects revenue still to be recognized under contracted or committed installation and replacement project work . project work generally lasts less than one year . service agreement revenue , service work and short duration projects , which are generally billed as performed , do not flow through backlog . accordingly , backlog represents only a portion of our revenue for any given future period , and it represents revenue that is likely to be reflected in our operating results over the next six to twelve months . as a result , we believe the predictive value of backlog information is limited to indications of general revenue direction over the near term and should not be interpreted as indicative of ongoing revenue performance over several quarters . backlog as of december 31 , 2018 was $ 1.17 billion , a 7.1 % decrease from september 30 , 2018 backlog of $ 1.25 billion and a 23.0 % increase from december 31 , 2017 backlog of $ 948.4 million . sequential backlog decreased primarily due to completion of project work at our wisconsin operation ( $ 25.5 million ) , our north carolina operation ( $ 25.1 million ) and one of our virginia operations ( $ 17.0 million ) . the year‑over‑year backlog increase included the indiana acquisition ( $ 27.2 million or 2.9 % ) . same-store backlog increased 20.1 % primarily due to increased project bookings at bch ( $ 68.5 million ) , one of our virginia operations ( $ 61.1 million ) and our alabama operation ( $ 33.9 million ) . gross profit —gross profit increased $ 80.0 million , or 21.8 % , to $ 446.3 million in 2018 as compared to 2017. the increase included a $ 12.0 million , or 3.3 % , increase related to the indiana and bch acquisitions and a $ 68.0 million , or 18.5 % , increase on a same‑store basis . the same‑store increase in gross profit was primarily due to increased volumes and improvement in project execution at our north carolina operation ( $ 23.3 million ) , bch ( $ 9.1 million ) and our wisconsin operation ( $ 6.8 million ) . as a percentage of revenue , gross profit remained relatively consistent at 20.4 % in 2018 as compared to 20.5 % in 2017 due to the improvement in project execution at our north carolina operation , offset by job underperformance at our california operation ( $ 3.7 million ) . selling , general and administrative expenses ( “ sg & a ” ) —sg & a increased $ 30.4 million , or 11.4 % , to $ 297.0 million for 2018 as compared to 2017. on a same‑store basis , excluding

debt revolving credit facility we have a $ 400.0 million senior credit facility ( the “ facility ” ) provided by a syndicate of banks , with a $ 100 million accordion option . the facility , which is available for borrowings and letters of credit , expires in april 2023 and is secured by a first lien on substantially all of our personal property except for assets related to projects subject to surety bonds and assets held by certain unrestricted subsidiaries and a second lien on our assets related to projects subject to surety bonds . in 2018 , we incurred approximately $ 0.8 million in financing and professional costs in connection with an amendment to the facility , which combined with the previous unamortized costs of $ 1.1 million , are being amortized on a straight-line basis as a non-cash charge to interest expense over the remaining term of the facility . as of december 31 , 2018 , we had $ 50.0 million of outstanding borrowings , $ 33.6 million in letters of credit outstanding and $ 316.4 million of credit available . there are two interest rate options for borrowings under the facility , the base rate loan option and the eurodollar rate loan option . these rates are floating rates determined by the broad financial markets , meaning they can and do move up and down from time to time . additional margins are then added to these two rates . the weighted average interest rate applicable to the borrowings under the facility was approximately 3.7 % as of december 31 , 2018. certain of our vendors require letters of credit to ensure reimbursement for amounts they are disbursing on our behalf , such as to beneficiaries under our self‑funded insurance programs . we have also occasionally used letters of credit to guarantee performance under our contracts and to ensure payment to our subcontractors and vendors under those contracts . our lenders issue such letters of credit through the facility for a fee .


 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.
     ```debt revolving credit facility we have a $ 400.0 million senior credit facility ( the “ facility ” ) provided by a syndicate of banks , with a $ 100 million accordion option . the facility , which is available for borrowings and letters of credit , expires in april 2023 and is secured by a first lien on substantially all of our personal property except for assets related to projects subject to surety bonds and assets held by certain unrestricted subsidiaries and a second lien on our assets related to projects subject to surety bonds . in 2018 , we incurred approximately $ 0.8 million in financing and professional costs in connection with an amendment to the facility , which combined with the previous unamortized costs of $ 1.1 million , are being amortized on a straight-line basis as a non-cash charge to interest expense over the remaining term of the facility . as of december 31 , 2018 , we had $ 50.0 million of outstanding borrowings , $ 33.6 million in letters of credit outstanding and $ 316.4 million of credit available . there are two interest rate options for borrowings under the facility , the base rate loan option and the eurodollar rate loan option . these rates are floating rates determined by the broad financial markets , meaning they can and do move up and down from time to time . additional margins are then added to these two rates . the weighted average interest rate applicable to the borrowings under the facility was approximately 3.7 % as of december 31 , 2018. certain of our vendors require letters of credit to ensure reimbursement for amounts they are disbursing on our behalf , such as to beneficiaries under our self‑funded insurance programs . we have also occasionally used letters of credit to guarantee performance under our contracts and to ensure payment to our subcontractors and vendors under those contracts . our lenders issue such letters of credit through the facility for a fee .
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 Suspicious Activity Report : given the fixed price nature of much of our project work , if our initial estimate of project costs is wrong or we incur cost overruns that can not be recovered in change orders , we can experience reduced profits or even significant losses on fixed price project work . we also perform some project work on a cost‑plus or a time and materials basis , under which we are paid our costs incurred plus an agreed‑upon profit margin , and such projects are sometimes subject to a guaranteed maximum cost . these margins are frequently less than fixed‑price contract margins because there is less risk of unrecoverable cost overruns in cost‑plus or time and materials work . as of december 31 , 2018 , we had 5,208 projects in process . our average project takes six to nine months to complete , with an average contract price of approximately $ 597,000. our projects generally require working capital funding of equipment and labor costs . customer payments on periodic billings generally do not recover these costs until late in the job . our average project duration together with typical retention terms as discussed above generally allow us to complete the realization of revenue and earnings in cash within one year . we have what we believe is a well‑diversified distribution of revenue across end‑use sectors that we believe reduces our exposure to negative developments in any given sector . because of the integral nature of hvac and related controls systems to most buildings , we have the legal right in almost all cases to attach liens to buildings or related funding sources when we have not been fully paid for installing systems , except with respect to some government buildings . the service work that we do , which is discussed further below , usually does not give rise to lien rights . we also perform larger projects . taken together , projects with contract prices of $ 1 million or more totaled $ 2.51 billion of aggregate contract value as of december 31 , 2018 , or approximately 80 % , out of a total contract value for all projects in progress of $ 3.11 billion . generally , projects closer in size to $ 1 million will be completed in one year or less . it is unusual for us to work on a project that exceeds two years in length . a stratification of projects in progress as of december 31 , 2018 , by contract price , is as follows : replace_table_token_6_th 25 in addition to project work , approximately 16.0 % of our revenue represents maintenance and repair service on already installed hvac and controls systems . this kind of work usually takes from a few hours to a few days to perform . prices to the customer are based on the equipment and materials used in the service as well as technician labor time . we usually bill the customer for service work when it is complete , typically with payment terms of up to thirty days . we also provide maintenance and repair service under ongoing contracts . under these contracts , we are paid regular monthly or quarterly amounts and provide specified service based on customer requirements . these agreements typically are for one or more years and frequently contain thirty‑ to sixty‑day cancellation notice periods . a relatively small portion of our revenue comes from national and regional account customers . these customers typically have multiple sites , and contract with us to perform maintenance and repair service . these contracts may also provide for us to perform new or replacement systems installation . we operate a national call center to dispatch technicians to sites requiring service . we perform the majority of this work with our own employees , with the balance being subcontracted to third parties that meet our performance qualifications . profile and management of our operations we manage our 36 operating units based on a variety of factors . financial measures we emphasize include profitability , and use of capital as indicated by cash flow and by other measures of working capital principally involving project cost , billings and receivables . we also monitor selling , general , administrative and indirect project support expense , backlog , workforce size and mix , growth in revenue and profits , variation of actual project cost from original estimate , and overall financial performance in comparison to budget and updated forecasts . operational factors we emphasize include project selection , estimating , pricing , management and execution practices , labor utilization , safety , training , and the make‑up of both existing backlog as well as new business being pursued , in terms of project size , technical application and facility type , end‑use customers and industries , and location of the work . most of our operations compete on a local or regional basis . attracting and retaining effective operating unit managers is an important factor in our business , particularly in view of the relative uniqueness of each market and operation , the importance of relationships with customers and other market participants such as architects and consulting engineers , and the high degree of competition and low barriers to entry in most of our markets . accordingly , we devote considerable attention to operating unit management quality , stability , and contingency planning , including related considerations of compensation , and non‑competition protection where applicable . economic and industry factors as a mechanical and building controls services provider , we operate in the broader nonresidential construction services industry and are affected by trends in this sector . while we do not have operations in all major cities of the united states , we believe our national presence is sufficiently large that we experience trends in demand for and pricing of our services that are consistent with trends in the national nonresidential construction sector . story_separator_special_tag if we conclude otherwise , then we perform the first step of a two‑step impairment test by calculating the fair value of the reporting unit and comparing the fair value with the carrying value of the reporting unit . we estimate the fair value of the reporting unit based on a market approach and an income approach , which utilizes discounted future cash flows . assumptions critical to the fair value estimates under the discounted cash flow model include discount rates , cash flow projections , projected long‑term growth rates and the determination of terminal values . the market approach utilized market multiples of invested capital from comparable publicly traded companies ( “ public company approach ” ) . the market multiples from invested capital include revenue , book equity plus debt and earnings before interest , provision for income taxes , depreciation and amortization ( “ ebitda ” ) . there are significant inherent uncertainties and management judgment involved in estimating the fair value of each reporting unit . while we believe we have made reasonable estimates and assumptions to estimate the fair value of our reporting units , it is possible that a material change could occur . if actual results are not consistent with our current estimates and assumptions , or the current economic outlook worsens , goodwill impairment charges may be recorded in future periods . we amortize identifiable intangible assets with finite lives over their useful lives . changes in strategy and or market condition , may result in adjustments to recorded intangible asset balances or their useful lives . results of operations ( in thousands ) : replace_table_token_7_th 2018 compared to 2017 we had 36 operating locations as of december 31 , 2017. in the third quarter of 2018 , we completed one acquisition of a company that reports as a separate operating location in indiana ( the “ indiana acquisition ” ) . furthermore , in the fourth quarter of 2018 , we combined two operating locations into one . as of december 31 , 2018 , we had 36 operating locations . acquisitions are included in our results of operations from the respective acquisition date . the same‑store comparison from 2018 to 2017 , as described below , excludes six months of results for the indiana acquisition , which was acquired in july 2018 , as well as the first three months of 2018 for bch , which was acquired in april 2017. an operating location is included in the same‑store comparison on the first day it has comparable prior year operating data , except for immaterial acquisitions that were absorbed and integrated , or “ tucked-in , ” with existing operations . 30 revenue —revenue increased $ 395.0 million , or 22.1 % to $ 2.18 billion in 2018 compared to 2017. the increase included a 5.1 % increase related to the indiana and bch acquisitions and a 17.0 % increase in revenue related to same‑store activity . the same‑store revenue increase was broad-based , including an increase in activity at our north carolina operation ( $ 123.6 million ) , one of our virginia operations ( $ 25.4 million ) and our wisconsin operation ( $ 23.0 million ) . backlog reflects revenue still to be recognized under contracted or committed installation and replacement project work . project work generally lasts less than one year . service agreement revenue , service work and short duration projects , which are generally billed as performed , do not flow through backlog . accordingly , backlog represents only a portion of our revenue for any given future period , and it represents revenue that is likely to be reflected in our operating results over the next six to twelve months . as a result , we believe the predictive value of backlog information is limited to indications of general revenue direction over the near term and should not be interpreted as indicative of ongoing revenue performance over several quarters . backlog as of december 31 , 2018 was $ 1.17 billion , a 7.1 % decrease from september 30 , 2018 backlog of $ 1.25 billion and a 23.0 % increase from december 31 , 2017 backlog of $ 948.4 million . sequential backlog decreased primarily due to completion of project work at our wisconsin operation ( $ 25.5 million ) , our north carolina operation ( $ 25.1 million ) and one of our virginia operations ( $ 17.0 million ) . the year‑over‑year backlog increase included the indiana acquisition ( $ 27.2 million or 2.9 % ) . same-store backlog increased 20.1 % primarily due to increased project bookings at bch ( $ 68.5 million ) , one of our virginia operations ( $ 61.1 million ) and our alabama operation ( $ 33.9 million ) . gross profit —gross profit increased $ 80.0 million , or 21.8 % , to $ 446.3 million in 2018 as compared to 2017. the increase included a $ 12.0 million , or 3.3 % , increase related to the indiana and bch acquisitions and a $ 68.0 million , or 18.5 % , increase on a same‑store basis . the same‑store increase in gross profit was primarily due to increased volumes and improvement in project execution at our north carolina operation ( $ 23.3 million ) , bch ( $ 9.1 million ) and our wisconsin operation ( $ 6.8 million ) . as a percentage of revenue , gross profit remained relatively consistent at 20.4 % in 2018 as compared to 20.5 % in 2017 due to the improvement in project execution at our north carolina operation , offset by job underperformance at our california operation ( $ 3.7 million ) . selling , general and administrative expenses ( “ sg & a ” ) —sg & a increased $ 30.4 million , or 11.4 % , to $ 297.0 million for 2018 as compared to 2017. on a same‑store basis , excluding

