net cash flows provided by operating activities of $ 704.4 million for 2016 increased $ 154.7 million from 2015 due primarily to ( 1 ) improved operating performance and ( 2 ) lower supplier payments in 2016 compared to 2015 , partially offset by ( 1 ) the impact of excess tax benefits from stock plans , primarily due to our increased stock price , and ( 2 ) an increase in accounts receivable due to increased sales , primarily in the united states . net cash flows provided by operating activities of $ 549.7 million for 2015 decreased $ 472.6 million from 2014 due primarily to ( 1 ) the $ 750.0 million upfront payment received from medtronic under a litigation settlement agreement , and ( 2 ) a higher bonus payout in 2015 associated with 2014 performance . these decreases were partially offset by ( 1 ) income tax payments of $ 224.5 million made in 2014 related to the medtronic settlement , ( 2 ) improved operating performance in 2015 , and ( 3 ) the $ 50.0 million charitable contribution made in 2014 to the edwards lifesciences foundation . net cash used in investing activities of $ 211.7 million in 2016 consisted primarily of capital expenditures of $ 176.1 million and $ 41.3 million for the acquisition of intangible assets . net cash used in investing activities of $ 316.1 million in 2015 consisted primarily of a $ 320.1 million net payment associated with the acquisition of cardiaq , and capital expenditures of $ 102.7 million , partially offset by net proceeds from investments of $ 119.6 million . net cash used in investing activities of $ 633.0 million in 2014 consisted primarily of net purchases of investments of $ 527.4 million and capital expenditures of $ 82.9 million . net cash used in financing activities of $ 268.5 million in 2016 consisted primarily of purchases of treasury stock of $ 662.3 million , partially offset by ( 1 ) net proceeds from the issuance of debt of $ 222.1 million , ( 2 ) proceeds from stock plans of $ 103.3 million , and ( 3 ) the excess tax benefit from stock plans of $ 64.3 million . net cash used in financing activities of $ 158.6 million in 2015 consisted primarily of purchases of treasury stock of $ 280.1 million , partially offset by ( 1 ) proceeds from stock plans of $ 87.2 million , and ( 2 ) the excess tax benefit from stock plans of $ 41.3 million . net cash used in financing activities of $ 153.0 million in 2014 consisted primarily of purchases of treasury stock of $ 300.9 million , partially offset by ( 1 ) proceeds from stock plans of $ 113.3 million , and ( 2 ) the excess tax benefit from stock plans of $ 49.4 million ( including the realization of previously unrealized excess tax benefits ) . a summary of all of our contractual obligations and commercial commitments as of december 31 , 2016 were as follows ( in millions ) : .
what percentage of total contractual cash obligations is operating leases?
( a ) the amount included in 2018 2018less than 1 year 2019 2019 reflects anticipated contributions to our various pension plans . anticipated contributions beyond one year are not determinable . the total accrued benefit liability for our pension plans recognized as of december 31 , 2016 was $ 50.1 million . this amount is impacted .