{"pre_text": ["the net decrease in the 2016 effective tax rate was due , in part , to the 2016 asset impairments in the u.s .", "and to the current year benefit related to a restructuring of one of our brazilian businesses that increases tax basis in long-term assets .", "further , the 2015 rate was impacted by the items described below .", "see note 20 2014asset impairment expense for additional information regarding the 2016 u.s .", "asset impairments .", "income tax expense increased $ 101 million , or 27% ( 27 % ) , to $ 472 million in 2015 .", "the company's effective tax rates were 41% ( 41 % ) and 26% ( 26 % ) for the years ended december 31 , 2015 and 2014 , respectively .", "the net increase in the 2015 effective tax rate was due , in part , to the nondeductible 2015 impairment of goodwill at our u.s .", "utility , dp&l and chilean withholding taxes offset by the release of valuation allowance at certain of our businesses in brazil , vietnam and the u.s .", "further , the 2014 rate was impacted by the sale of approximately 45% ( 45 % ) of the company 2019s interest in masin aes pte ltd. , which owns the company 2019s business interests in the philippines and the 2014 sale of the company 2019s interests in four u.k .", "wind operating projects .", "neither of these transactions gave rise to income tax expense .", "see note 15 2014equity for additional information regarding the sale of approximately 45% ( 45 % ) of the company 2019s interest in masin-aes pte ltd .", "see note 23 2014dispositions for additional information regarding the sale of the company 2019s interests in four u.k .", "wind operating projects .", "our effective tax rate reflects the tax effect of significant operations outside the u.s. , which are generally taxed at rates lower than the u.s .", "statutory rate of 35% ( 35 % ) .", "a future proportionate change in the composition of income before income taxes from foreign and domestic tax jurisdictions could impact our periodic effective tax rate .", "the company also benefits from reduced tax rates in certain countries as a result of satisfying specific commitments regarding employment and capital investment .", "see note 21 2014income taxes for additional information regarding these reduced rates .", "foreign currency transaction gains ( losses ) foreign currency transaction gains ( losses ) in millions were as follows: ."], "post_text": ["total ( 1 ) $ ( 15 ) $ 107 $ 11 _____________________________ ( 1 ) includes gains of $ 17 million , $ 247 million and $ 172 million on foreign currency derivative contracts for the years ended december 31 , 2016 , 2015 and 2014 , respectively .", "the company recognized a net foreign currency transaction loss of $ 15 million for the year ended december 31 , 2016 primarily due to losses of $ 50 million at the aes corporation mainly due to remeasurement losses on intercompany notes , and losses on swaps and options .", "this loss was partially offset by gains of $ 37 million in argentina , mainly due to the favorable impact of foreign currency derivatives related to government receivables .", "the company recognized a net foreign currency transaction gain of $ 107 million for the year ended december 31 , 2015 primarily due to gains of : 2022 $ 124 million in argentina , due to the favorable impact from foreign currency derivatives related to government receivables , partially offset by losses from the devaluation of the argentine peso associated with u.s .", "dollar denominated debt , and losses at termoandes ( a u.s .", "dollar functional currency subsidiary ) primarily associated with cash and accounts receivable balances in local currency , 2022 $ 29 million in colombia , mainly due to the depreciation of the colombian peso , positively impacting chivor ( a u.s .", "dollar functional currency subsidiary ) due to liabilities denominated in colombian pesos , 2022 $ 11 million in the united kingdom , mainly due to the depreciation of the pound sterling , resulting in gains at ballylumford holdings ( a u.s .", "dollar functional currency subsidiary ) associated with intercompany notes payable denominated in pound sterling , and ."], "table": [["years ended december 31,", "2016", "2015", "2014"], ["aes corporation", "$ -50 ( 50 )", "$ -31 ( 31 )", "$ -34 ( 34 )"], ["chile", "-9 ( 9 )", "-18 ( 18 )", "-30 ( 30 )"], ["colombia", "-8 ( 8 )", "29", "17"], ["mexico", "-8 ( 8 )", "-6 ( 6 )", "-14 ( 14 )"], ["philippines", "12", "8", "11"], ["united kingdom", "13", "11", "12"], ["argentina", "37", "124", "66"], ["other", "-2 ( 2 )", "-10 ( 10 )", "-17 ( 17 )"], ["total ( 1 )", "$ -15 ( 15 )", "$ 107", "$ 11"]], "table_ori": [["Years Ended December 31,", "2016", "2015", "2014"], ["AES Corporation", "$(50)", "$(31)", "$(34)"], ["Chile", "(9)", "(18)", "(30)"], ["Colombia", "(8)", "29", "17"], ["Mexico", "(8)", "(6)", "(14)"], ["Philippines", "12", "8", "11"], ["United Kingdom", "13", "11", "12"], ["Argentina", "37", "124", "66"], ["Other", "(2)", "(10)", "(17)"], ["Total<sup>(1)</sup>", "$(15)", "$107", "$11"]]}

Question: what was the change in millions between 2015 and 2016 of foreign currency transaction gains ( losses ) for aes corporation?
Evidence:
table_1: years ended december 31 , the aes corporation of 2016 is $ -50 ( 50 ) ; the aes corporation of 2015 is $ -31 ( 31 ) ; the aes corporation of 2014 is $ -34 ( 34 ) ;
Program: subtract(-50, -31)
Answer:
str_answer: -19
exe_answer: -19