fidelity national information services , inc . and subsidiaries notes to consolidated financial statements - ( continued ) contingent consideration liabilities recorded in connection with business acquisitions must also be adjusted for changes in fair value until settled . see note 3 for discussion of the capital markets company bvba ( "capco" ) contingent consideration liability . ( d ) derivative financial instruments the company accounts for derivative financial instruments in accordance with financial accounting standards board accounting standards codification ( 201cfasb asc 201d ) topic 815 , derivatives and hedging . during 2016 , 2015 and 2014 , the company engaged in g hedging activities relating to its variable rate debt through the use of interest rate swaps . the company designates these interest rate swaps as cash flow hedges . the estimated fair values of the cash flow hedges are determined using level 2 type measurements . thh ey are recorded as an asset or liability of the company and are included in the accompanying consolidated balance sheets in prepaid expenses and other current assets , other non-current assets , accounts payable and accrued liabilities or other long-term liabilities , as appropriate , and as a component of accumulated other comprehensive earnings , net of deferred taxes . a portion of the amount included in accumulated other comprehensive earnings is recorded in interest expense as a yield adjustment as interest payments are made on then company 2019s term and revolving loans ( note 10 ) . the company 2019s existing cash flow hedge is highly effective and there was no impact on 2016 earnings due to hedge ineffectiveness . it is our policy to execute such instruments with credit-worthy banks and not to enter into derivative financial instruments for speculative purposes . as of december 31 , 2016 , we believe that our interest rate swap counterparty will be able to fulfill its obligations under our agreement . the company's foreign exchange risk management policy permits the use of derivative instruments , such as forward contracts and options , to reduce volatility in the company's results of operations and/or cash flows resulting from foreign exchange rate fluctuations . during 2016 and 2015 , the company entered into foreign currency forward exchange contracts to hedge foreign currency exposure to intercompany loans . as of december 31 , 2016 and 2015 , the notional amount of these derivatives was approximately $ 143 million and aa $ 81 million , respectively , and the fair value was nominal . these derivatives have not been designated as hedges for accounting purposes . we also use currency forward contracts to manage our exposure to fluctuations in costs caused by variations in indian rupee ( "inr" ) ii exchange rates . as of december 31 , 2016 , the notional amount of these derivatives was approximately $ 7 million and the fair value was l less than $ 1 million , which is included in prepaid expenses and other current assets in the consolidated balance sheets . these inr forward contracts are designated as cash flow hedges . the fair value of these currency forward contracts is determined using currency uu exchange market rates , obtained from reliable , independent , third party banks , at the balance sheet date . the fair value of forward rr contracts is subject to changes in currency exchange rates . the company has no ineffectiveness related to its use of currency forward ff contracts in connection with inr cash flow hedges . in september 2015 , the company entered into treasury lock hedges with a total notional amount of $ 1.0 billion , reducing the risk of changes in the benchmark index component of the 10-year treasury yield . the company def signated these derivatives as cash flow hedges . on october 13 , 2015 , in conjunction with the pricing of the $ 4.5 billion senior notes , the companyr terminated these treasury lock contracts for a cash settlement payment of $ 16 million , which was recorded as a component of other comprehensive earnings and will be reclassified as an adjustment to interest expense over the ten years during which the related interest payments that were hedged will be recognized in income . ( e ) trade receivables a summary of trade receivables , net , as of december 31 , 2016 and 2015 is as follows ( in millions ) : .

Table:
 | 2016 | 2015
trade receivables 2014 billed | $ 1452 | $ 1546
trade receivables 2014 unbilled | 228 | 201
total trade receivables | 1680 | 1747
allowance for doubtful accounts | -41 ( 41 ) | -16 ( 16 )
total trade receivables net | $ 1639 | $ 1731
.

Question: what was the change in millions of total trade receivables net from 2015 to 2016?
Answer: -92
Calculation: subtract(1639, 1731)