{"pre_text": ["income taxes american water and its subsidiaries participate in a consolidated federal income tax return for u.s .", "tax purposes .", "members of the consolidated group are charged with the amount of federal income tax expense determined as if they filed separate returns .", "certain income and expense items are accounted for in different time periods for financial reporting than for income tax reporting purposes .", "the company provides deferred income taxes on the difference between the tax basis of assets and liabilities and the amounts at which they are carried in the financial statements .", "these deferred income taxes are based on the enacted tax rates expected to be in effect when these temporary differences are projected to reverse .", "in addition , the regulated utility subsidiaries recognize regulatory assets and liabilities for the effect on revenues expected to be realized as the tax effects of temporary differences , previously flowed through to customers , reverse .", "investment tax credits have been deferred by the regulated utility subsidiaries and are being amortized to income over the average estimated service lives of the related assets .", "the company recognizes accrued interest and penalties related to tax positions as a component of income tax expense and accounts for sales tax collected from customers and remitted to taxing authorities on a net basis .", "see note 13 2014income taxes .", "allowance for funds used during construction afudc is a non-cash credit to income with a corresponding charge to utility plant that represents the cost of borrowed funds or a return on equity funds devoted to plant under construction .", "the regulated utility subsidiaries record afudc to the extent permitted by the pucs .", "the portion of afudc attributable to borrowed funds is shown as a reduction of interest , net in the accompanying consolidated statements of operations .", "any portion of afudc attributable to equity funds would be included in other income ( expenses ) in the accompanying consolidated statements of operations .", "afudc is summarized in the following table for the years ended december 31: ."], "post_text": ["environmental costs the company 2019s water and wastewater operations and the operations of its market-based businesses are subject to u.s .", "federal , state , local and foreign requirements relating to environmental protection , and as such , the company periodically becomes subject to environmental claims in the normal course of business .", "environmental expenditures that relate to current operations or provide a future benefit are expensed or capitalized as appropriate .", "remediation costs that relate to an existing condition caused by past operations are accrued , on an undiscounted basis , when it is probable that these costs will be incurred and can be reasonably estimated .", "a conservation agreement entered into by a subsidiary of the company with the national oceanic and atmospheric administration in 2010 and amended in 2017 required the company to , among other provisions , implement certain measures to protect the steelhead trout and its habitat in the carmel river watershed in the state of california .", "the company agreed to pay $ 1 million annually commencing in 2010 with the final payment being made in 2021 .", "remediation costs accrued amounted to $ 6 million and less than $ 1 million as of december 31 , 2017 and 2016 , respectively .", "derivative financial instruments the company uses derivative financial instruments for purposes of hedging exposures to fluctuations in interest rates .", "these derivative contracts are entered into for periods consistent with the related underlying ."], "table": [["", "2017", "2016", "2015"], ["allowance for other funds used during construction", "$ 19", "$ 15", "$ 13"], ["allowance for borrowed funds used during construction", "8", "6", "8"]], "table_ori": [["", "2017", "2016", "2015"], ["Allowance for other funds used during construction", "$19", "$15", "$13"], ["Allowance for borrowed funds used during construction", "8", "6", "8"]]}

Question: what was the combined amount of allowance for funds used in and funds borrowed in construction in 2016
Evidence:
table_1: the allowance for other funds used during construction of 2017 is $ 19 ; the allowance for other funds used during construction of 2016 is $ 15 ; the allowance for other funds used during construction of 2015 is $ 13 ;
Program: add(15, const_6)
Answer:
str_answer: 21
exe_answer: 21