we refine cst into terpene fractions , which can be further upgraded into terpene resins . the various fractions and derivatives resulting from our cto and cst refining process provide for distinct functionalities and properties , determining their respective applications and end markets . we focus our resources on four product groups : adhesives ; roads and construction ; tires ; and performance chemicals . within our product groups , our products are sold into a diverse range of submarkets , including packaging , tapes and labels , pavement marking , high performance tires , fuel additives , oilfield and mining , coatings , metalworking fluids and lubricants , inks , and flavor and fragrances , among others . while this business is based predominantly on the refining and upgrading of cto and cst , we have the capacity to use both hydrocarbon-based raw materials , such as alpha-methyl-styrene , rosins , and gum rosins where appropriate and , accordingly , are able to offer tailored solutions for our customers . 32 status of synergies , operational improvement , and cost reduction initiatives we previously announced synergies and operational improvement initiatives associated with the arizona chemical acquisition and a cost reduction initiative targeted at lowering costs in our polymer segment . the polymer segment cost reduction initiative began in 2015 with a total target savings of $ 70 million to be realized by the end of 2018. we realized approximately $ 45.0 million to date and we currently anticipate we will realize a significant portion of the remaining savings in 2018. in conjunction with the acquisition of arizona chemical , we identified $ 65 million of cost-based synergies , approximately $ 25 million of which relate to general and administrative costs , and approximately $ 40 million of which are associated with operation cost improvements ; all of which has been realized as of december 31 , 2017. results of operations factors affecting our results of operations raw materials . we use butadiene , styrene , and isoprene in our polymer segment and cto and cst in our chemical segment as our primary raw materials . the cost of these raw materials has generally correlated with changes in energy prices and is generally influenced by supply and demand factors and for our isoprene monomers the prices for natural and synthetic rubber . average purchase prices of our raw materials increased during 2017 compared to 2016 and were lower in 2016 compared to 2015 . we use the fifo basis of accounting for inventory and cost of goods sold , and therefore gross profit . in periods of raw material price volatility , reported results under fifo will differ from what the results would have been if cost of goods sold were based on ecrc . specifically , in periods of rising raw material costs , reported gross profit will be higher under fifo than under ecrc . conversely , in periods of declining raw material costs , reported gross profit will be lower under fifo than under ecrc . in recognition of the fact that the cost of raw materials affects our results of operations and the comparability of our results of operations , we provide the difference , or spread , between fifo and ecrc to arrive at our adjusted ebitda . international operations and currency fluctuations . we operate a geographically diverse business , serving customers in numerous countries from fourteen manufacturing facilities on four continents . our sales and production costs are mainly denominated in u.s. dollars , euro , japanese yen , swedish krona , and brazilian real . from time to time , we use hedging strategies to reduce our exposure to currency fluctuations . we generated our revenue from customers located in the following regions : replace_table_token_14_th seasonality . seasonal changes and weather conditions typically affect our sales of products in our paving , pavement markings , roofing , and construction applications , which generally results in higher sales volumes in the second and third quarters of the calendar year compared to the first and fourth quarters of the calendar year . sales for our other product applications tend to show relatively little seasonality . 33 kraton corporation consolidated statements of operations ( in thousands , except per share data ) replace_table_token_15_th consolidated results year ended december 31 , 2017 compared to year ended december 31 , 2016 our operating results for the year ended december 31 , 2016 include the operating results for arizona chemical since the acquisition date of january 6 , 2016 . revenue was $ 1,960.4 million for the year ended december 31 , 2017 compared to $ 1,744.1 million for the year ended december 31 , 2016 , an increase of $ 216.3 million , or 12.4 % . revenue for the polymer segment increase d $ 174.9 million and revenue for the chemical segment increase d $ 41.3 million . for additional information regarding the changes in revenue , see our segment disclosures below . cost of goods sold was $ 1,418.5 million for the year ended december 31 , 2017 compared to $ 1,265.1 million for the year ended december 31 , 2016 , an increase of $ 153.4 million , or 12.1 % . the increase was primarily driven by higher average raw material costs and sales volumes , partially offset by the $ 24.7 million of higher costs of goods sold in 2016 related to the fair value adjustment in purchase accounting for inventory . selling , general , and administrative expenses were $ 161.9 million for the year ended december 31 , 2017 compared to $ 177.6 million for the year ended december 31 , 2016 . the $ 15.7 million decrease is primarily attributable to lower transaction , acquisition , and restructuring costs , partially offset by higher employee related costs . story_separator_special_tag sales volumes were 324.2 kilotons for the year ended december 31 , 2016 , an increase of 17.7 kilotons , or 5.8 % . with respect to revenue for the polymer segment product groups : cariflex revenue was $ 171.0 million for the year ended december 31 , 2016 compared to $ 142.9 million for the year ended december 31 , 2015. the increase of $ 28.1 million was attributable to a 19.3 % increase in sales volumes , primarily due to higher sales into surgical glove applications , and changes in foreign currency of $ 5.3 million , partially offset by a $ 5.1 million decrease attributable to lower average selling prices resulting from lower raw material costs . specialty polymers revenue was $ 340.3 million for the year ended december 31 , 2016 compared to $ 350.7 million for the year ended december 31 , 2015 , a decrease of $ 10.4 million . excluding the $ 9.9 million effect of the sale of bcu , revenue was essentially unchanged . revenue associated with a 6.9 % increase in sales volume , primarily into automotive and consumer applications , was essentially offset by the impact of lower average selling prices associated with product mix and to a lesser extent lower raw material cost . changes in currency exchange rates had a $ 1.5 million negative effect on revenue . performance products revenue was $ 513.1 million for the year ended december 31 , 2016 compared to $ 540.6 million for the year ended december 31 , 2015. the $ 27.5 million decline was primarily driven by a lower average selling prices of $ 50.7 million , resulting from lower prices for certain sis product grades , product mix , and raw material costs , partially offset by a 4.3 % increase in sales volumes . the increase in sales volumes was primarily driven by paving , roofing , and personal care applications , partially offset by lower sales of sis product grades into packaging and industrial adhesive applications . changes in foreign currency exchange rates had a $ 0.8 million negative effect on revenue . for the year ended december 31 , 2016 , the polymer segment operating income was $ 77.9 million compared to $ 18.2 million for the year ended december 31 , 2015. for the year ended december 31 , 2016 , the polymer segment generated $ 183.1 million of adjusted ebitda ( non-gaap ) compared to $ 166.8 million for the year ended december 31 , 2015 , an increase of $ 16.3 million , or 9.8 % . the effect of currency fluctuations negatively impacted adjusted ebitda ( non-gaap ) by $ 6.5 million . see item 6. selected financial data for a reconciliation of u.s. gaap operating income to adjusted ebitda ( non-gaap ) . 38 chemical segment the following results of operations for the chemical segment have been included in our consolidated results effective as of the date of the acquisition , january 6 , 2016 . replace_table_token_17_th ( 1 ) see item 6. selected financial data for a reconciliation of u.s. gaap operating income to non-gaap adjusted ebitda . ( 2 ) defined as adjusted ebitda as a percentage of revenue . year ended december 31 , 2017 compared to year ended december 31 , 2016 revenue for the chemical segment was $ 760.7 million for the year ended december 31 , 2017 compared to $ 719.4 million for the year ended december 31 , 2016 . sales volumes were 426.4 kilotons for the year ended december 31 , 2017 , an increase of 14.9 kilotons or 3.6 % . adhesives volumes increase d 7.2 % , performance chemicals volumes increase d 2.0 % , roads and construction volumes increase d 2.6 % , and tires volumes increase d 10.0 % . with respect to revenue for the chemical segment product groups : adhesives revenue was $ 253.0 million for the year ended december 31 , 2017 compared to $ 246.4 million for the year ended december 31 , 2016 . the increase was primarily driven by improved sales volumes . performance chemicals revenue was $ 409.6 million for the year ended december 31 , 2017 compared to $ 381.5 million for the year ended december 31 , 2016 . the increase was primarily attributable to higher average selling prices and to a lesser extent improved sales volumes . roads and construction revenue was $ 48.2 million for the year ended december 31 , 2017 compared to $ 48.9 million for the year ended december 31 , 2016 , which was essentially flat . tires revenue was $ 50.0 million for the year ended december 31 , 2017 compared to $ 42.5 million for the year ended december 31 , 2016 . the increase was driven by improved sales volumes and higher average selling prices . for the year ended december 31 , 2017 , the chemical segment operating income was $ 84.7 million compared to $ 58.4 million for the year ended december 31 , 2016 . for the year ended december 31 , 2017 , the chemical segment generated $ 151.2 million of adjusted ebitda ( non-gaap ) compared to $ 171.0 million for the year ended december 31 , 2016 . the decrease in adjusted ebitda was primarily due to lower margins indicative of the impact of low-cost c5/c9 hydrocarbon alternatives and pricing pressure for tofa and tor products , which more than offset the increase in sales volumes . see item 6. selected financial data for a reconciliation of u.s. gaap operating income to non-gaap adjusted ebitda . 39 critical accounting policies the preparation of these financial statements in conformity with u.s. gaap requires management to make assumptions and estimates that directly affect the amounts reported in the consolidated financial statements . certain critical accounting policies requiring significant judgments , estimates , and assumptions are described in this section . we consider an accounting estimate to

net cash provided by operating activities totaled $ 138.5 million for the year ended december 31 , 2016 and $ 103.8 million for the year ended december 31 , 2015 . this represents a net increase of $ 34.6 million , which was primarily driven by increases in operating income and changes in working capital . the net change in working capital was a use of cash flows of $ 3.7 million in 2016 compared to a source of cash of $ 46.1 million in 2015 ; a period-over-period decrease in cash flows of $ 49.8 million . the period-over-period changes are as follows : $ 44.7 million decrease in cash flows for other payables and accruals primarily due to the timing of payments related to transaction related costs ; $ 21.3 million decrease in cash flows associated with inventories of products , materials , and supplies , due to higher raw material costs in our polymer segment , partially offset by lower inventory volumes in our polymer and chemical segments ; and $ 4.9 million decrease in cash flows due to the timing of payments of other items , including accounts receivable , related party transactions , taxes , and pension costs ; partially offset by a $ 21.1 million increase in cash flows associated with trade accounts payable due to higher raw material costs in our polymer segment and timing of payments . investing cash flows net cash used in investing activities totaled $ 122.6 million , $ 1,364.8 million , and $ 128.7 million for the years ended december 31 , 2017 , 2016 , and 2015 , respectively .


 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.
     ```net cash provided by operating activities totaled $ 138.5 million for the year ended december 31 , 2016 and $ 103.8 million for the year ended december 31 , 2015 . this represents a net increase of $ 34.6 million , which was primarily driven by increases in operating income and changes in working capital . the net change in working capital was a use of cash flows of $ 3.7 million in 2016 compared to a source of cash of $ 46.1 million in 2015 ; a period-over-period decrease in cash flows of $ 49.8 million . the period-over-period changes are as follows : $ 44.7 million decrease in cash flows for other payables and accruals primarily due to the timing of payments related to transaction related costs ; $ 21.3 million decrease in cash flows associated with inventories of products , materials , and supplies , due to higher raw material costs in our polymer segment , partially offset by lower inventory volumes in our polymer and chemical segments ; and $ 4.9 million decrease in cash flows due to the timing of payments of other items , including accounts receivable , related party transactions , taxes , and pension costs ; partially offset by a $ 21.1 million increase in cash flows associated with trade accounts payable due to higher raw material costs in our polymer segment and timing of payments . investing cash flows net cash used in investing activities totaled $ 122.6 million , $ 1,364.8 million , and $ 128.7 million for the years ended december 31 , 2017 , 2016 , and 2015 , respectively .
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 Suspicious Activity Report : we refine cst into terpene fractions , which can be further upgraded into terpene resins . the various fractions and derivatives resulting from our cto and cst refining process provide for distinct functionalities and properties , determining their respective applications and end markets . we focus our resources on four product groups : adhesives ; roads and construction ; tires ; and performance chemicals . within our product groups , our products are sold into a diverse range of submarkets , including packaging , tapes and labels , pavement marking , high performance tires , fuel additives , oilfield and mining , coatings , metalworking fluids and lubricants , inks , and flavor and fragrances , among others . while this business is based predominantly on the refining and upgrading of cto and cst , we have the capacity to use both hydrocarbon-based raw materials , such as alpha-methyl-styrene , rosins , and gum rosins where appropriate and , accordingly , are able to offer tailored solutions for our customers . 32 status of synergies , operational improvement , and cost reduction initiatives we previously announced synergies and operational improvement initiatives associated with the arizona chemical acquisition and a cost reduction initiative targeted at lowering costs in our polymer segment . the polymer segment cost reduction initiative began in 2015 with a total target savings of $ 70 million to be realized by the end of 2018. we realized approximately $ 45.0 million to date and we currently anticipate we will realize a significant portion of the remaining savings in 2018. in conjunction with the acquisition of arizona chemical , we identified $ 65 million of cost-based synergies , approximately $ 25 million of which relate to general and administrative costs , and approximately $ 40 million of which are associated with operation cost improvements ; all of which has been realized as of december 31 , 2017. results of operations factors affecting our results of operations raw materials . we use butadiene , styrene , and isoprene in our polymer segment and cto and cst in our chemical segment as our primary raw materials . the cost of these raw materials has generally correlated with changes in energy prices and is generally influenced by supply and demand factors and for our isoprene monomers the prices for natural and synthetic rubber . average purchase prices of our raw materials increased during 2017 compared to 2016 and were lower in 2016 compared to 2015 . we use the fifo basis of accounting for inventory and cost of goods sold , and therefore gross profit . in periods of raw material price volatility , reported results under fifo will differ from what the results would have been if cost of goods sold were based on ecrc . specifically , in periods of rising raw material costs , reported gross profit will be higher under fifo than under ecrc . conversely , in periods of declining raw material costs , reported gross profit will be lower under fifo than under ecrc . in recognition of the fact that the cost of raw materials affects our results of operations and the comparability of our results of operations , we provide the difference , or spread , between fifo and ecrc to arrive at our adjusted ebitda . international operations and currency fluctuations . we operate a geographically diverse business , serving customers in numerous countries from fourteen manufacturing facilities on four continents . our sales and production costs are mainly denominated in u.s. dollars , euro , japanese yen , swedish krona , and brazilian real . from time to time , we use hedging strategies to reduce our exposure to currency fluctuations . we generated our revenue from customers located in the following regions : replace_table_token_14_th seasonality . seasonal changes and weather conditions typically affect our sales of products in our paving , pavement markings , roofing , and construction applications , which generally results in higher sales volumes in the second and third quarters of the calendar year compared to the first and fourth quarters of the calendar year . sales for our other product applications tend to show relatively little seasonality . 33 kraton corporation consolidated statements of operations ( in thousands , except per share data ) replace_table_token_15_th consolidated results year ended december 31 , 2017 compared to year ended december 31 , 2016 our operating results for the year ended december 31 , 2016 include the operating results for arizona chemical since the acquisition date of january 6 , 2016 . revenue was $ 1,960.4 million for the year ended december 31 , 2017 compared to $ 1,744.1 million for the year ended december 31 , 2016 , an increase of $ 216.3 million , or 12.4 % . revenue for the polymer segment increase d $ 174.9 million and revenue for the chemical segment increase d $ 41.3 million . for additional information regarding the changes in revenue , see our segment disclosures below . cost of goods sold was $ 1,418.5 million for the year ended december 31 , 2017 compared to $ 1,265.1 million for the year ended december 31 , 2016 , an increase of $ 153.4 million , or 12.1 % . the increase was primarily driven by higher average raw material costs and sales volumes , partially offset by the $ 24.7 million of higher costs of goods sold in 2016 related to the fair value adjustment in purchase accounting for inventory . selling , general , and administrative expenses were $ 161.9 million for the year ended december 31 , 2017 compared to $ 177.6 million for the year ended december 31 , 2016 . the $ 15.7 million decrease is primarily attributable to lower transaction , acquisition , and restructuring costs , partially offset by higher employee related costs . story_separator_special_tag sales volumes were 324.2 kilotons for the year ended december 31 , 2016 , an increase of 17.7 kilotons , or 5.8 % . with respect to revenue for the polymer segment product groups : cariflex revenue was $ 171.0 million for the year ended december 31 , 2016 compared to $ 142.9 million for the year ended december 31 , 2015. the increase of $ 28.1 million was attributable to a 19.3 % increase in sales volumes , primarily due to higher sales into surgical glove applications , and changes in foreign currency of $ 5.3 million , partially offset by a $ 5.1 million decrease attributable to lower average selling prices resulting from lower raw material costs . specialty polymers revenue was $ 340.3 million for the year ended december 31 , 2016 compared to $ 350.7 million for the year ended december 31 , 2015 , a decrease of $ 10.4 million . excluding the $ 9.9 million effect of the sale of bcu , revenue was essentially unchanged . revenue associated with a 6.9 % increase in sales volume , primarily into automotive and consumer applications , was essentially offset by the impact of lower average selling prices associated with product mix and to a lesser extent lower raw material cost . changes in currency exchange rates had a $ 1.5 million negative effect on revenue . performance products revenue was $ 513.1 million for the year ended december 31 , 2016 compared to $ 540.6 million for the year ended december 31 , 2015. the $ 27.5 million decline was primarily driven by a lower average selling prices of $ 50.7 million , resulting from lower prices for certain sis product grades , product mix , and raw material costs , partially offset by a 4.3 % increase in sales volumes . the increase in sales volumes was primarily driven by paving , roofing , and personal care applications , partially offset by lower sales of sis product grades into packaging and industrial adhesive applications . changes in foreign currency exchange rates had a $ 0.8 million negative effect on revenue . for the year ended december 31 , 2016 , the polymer segment operating income was $ 77.9 million compared to $ 18.2 million for the year ended december 31 , 2015. for the year ended december 31 , 2016 , the polymer segment generated $ 183.1 million of adjusted ebitda ( non-gaap ) compared to $ 166.8 million for the year ended december 31 , 2015 , an increase of $ 16.3 million , or 9.8 % . the effect of currency fluctuations negatively impacted adjusted ebitda ( non-gaap ) by $ 6.5 million . see item 6. selected financial data for a reconciliation of u.s. gaap operating income to adjusted ebitda ( non-gaap ) . 38 chemical segment the following results of operations for the chemical segment have been included in our consolidated results effective as of the date of the acquisition , january 6 , 2016 . replace_table_token_17_th ( 1 ) see item 6. selected financial data for a reconciliation of u.s. gaap operating income to non-gaap adjusted ebitda . ( 2 ) defined as adjusted ebitda as a percentage of revenue . year ended december 31 , 2017 compared to year ended december 31 , 2016 revenue for the chemical segment was $ 760.7 million for the year ended december 31 , 2017 compared to $ 719.4 million for the year ended december 31 , 2016 . sales volumes were 426.4 kilotons for the year ended december 31 , 2017 , an increase of 14.9 kilotons or 3.6 % . adhesives volumes increase d 7.2 % , performance chemicals volumes increase d 2.0 % , roads and construction volumes increase d 2.6 % , and tires volumes increase d 10.0 % . with respect to revenue for the chemical segment product groups : adhesives revenue was $ 253.0 million for the year ended december 31 , 2017 compared to $ 246.4 million for the year ended december 31 , 2016 . the increase was primarily driven by improved sales volumes . performance chemicals revenue was $ 409.6 million for the year ended december 31 , 2017 compared to $ 381.5 million for the year ended december 31 , 2016 . the increase was primarily attributable to higher average selling prices and to a lesser extent improved sales volumes . roads and construction revenue was $ 48.2 million for the year ended december 31 , 2017 compared to $ 48.9 million for the year ended december 31 , 2016 , which was essentially flat . tires revenue was $ 50.0 million for the year ended december 31 , 2017 compared to $ 42.5 million for the year ended december 31 , 2016 . the increase was driven by improved sales volumes and higher average selling prices . for the year ended december 31 , 2017 , the chemical segment operating income was $ 84.7 million compared to $ 58.4 million for the year ended december 31 , 2016 . for the year ended december 31 , 2017 , the chemical segment generated $ 151.2 million of adjusted ebitda ( non-gaap ) compared to $ 171.0 million for the year ended december 31 , 2016 . the decrease in adjusted ebitda was primarily due to lower margins indicative of the impact of low-cost c5/c9 hydrocarbon alternatives and pricing pressure for tofa and tor products , which more than offset the increase in sales volumes . see item 6. selected financial data for a reconciliation of u.s. gaap operating income to non-gaap adjusted ebitda . 39 critical accounting policies the preparation of these financial statements in conformity with u.s. gaap requires management to make assumptions and estimates that directly affect the amounts reported in the consolidated financial statements . certain critical accounting policies requiring significant judgments , estimates , and assumptions are described in this section . we consider an accounting estimate to

