{"pre_text": ["devon energy corporation and subsidiaries notes to consolidated financial statements 2013 ( continued ) debt maturities as of december 31 , 2015 , excluding premiums and discounts , are as follows ( millions ) : ."], "post_text": ["credit lines devon has a $ 3.0 billion senior credit facility .", "the maturity date for $ 30 million of the senior credit facility is october 24 , 2017 .", "the maturity date for $ 164 million of the senior credit facility is october 24 , 2018 .", "the maturity date for the remaining $ 2.8 billion is october 24 , 2019 .", "amounts borrowed under the senior credit facility may , at the election of devon , bear interest at various fixed rate options for periods of up to twelve months .", "such rates are generally less than the prime rate .", "however , devon may elect to borrow at the prime rate .", "the senior credit facility currently provides for an annual facility fee of $ 3.8 million that is payable quarterly in arrears .", "as of december 31 , 2015 , there were no borrowings under the senior credit facility .", "the senior credit facility contains only one material financial covenant .", "this covenant requires devon 2019s ratio of total funded debt to total capitalization , as defined in the credit agreement , to be no greater than 65% ( 65 % ) .", "the credit agreement contains definitions of total funded debt and total capitalization that include adjustments to the respective amounts reported in the accompanying consolidated financial statements .", "also , total capitalization is adjusted to add back noncash financial write-downs such as full cost ceiling impairments or goodwill impairments .", "as of december 31 , 2015 , devon was in compliance with this covenant with a debt-to- capitalization ratio of 23.7% ( 23.7 % ) .", "commercial paper devon 2019s senior credit facility supports its $ 3.0 billion of short-term credit under its commercial paper program .", "commercial paper debt generally has a maturity of between 1 and 90 days , although it can have a maturity of up to 365 days , and bears interest at rates agreed to at the time of the borrowing .", "the interest rate is generally based on a standard index such as the federal funds rate , libor or the money market rate as found in the commercial paper market .", "as of december 31 , 2015 , devon 2019s outstanding commercial paper borrowings had a weighted-average borrowing rate of 0.63% ( 0.63 % ) .", "issuance of senior notes in june 2015 , devon issued $ 750 million of 5.0% ( 5.0 % ) senior notes due 2045 that are unsecured and unsubordinated obligations .", "devon used the net proceeds to repay the floating rate senior notes that matured on december 15 , 2015 , as well as outstanding commercial paper balances .", "in december 2015 , in conjunction with the announcement of the powder river basin and stack acquisitions , devon issued $ 850 million of 5.85% ( 5.85 % ) senior notes due 2025 that are unsecured and unsubordinated obligations .", "devon used the net proceeds to fund the cash portion of these acquisitions. ."], "table": [["2016", "$ 976"], ["2017", "2014"], ["2018", "875"], ["2019", "1100"], ["2020", "414"], ["thereafter", "9763"], ["total", "$ 13128"]], "table_ori": [["2016", "$976"], ["2017", "—"], ["2018", "875"], ["2019", "1,100"], ["2020", "414"], ["Thereafter", "9,763"], ["Total", "$13,128"]]}

Question: in millions , what was the mathematical range of debt maturities for 2018-2020?
Evidence:
table_2: 2016 the 2018 of $ 976 is 875 ;
table_3: 2016 the 2019 of $ 976 is 1100 ;
table_4: 2016 the 2020 of $ 976 is 414 ;
text_0: devon energy corporation and subsidiaries notes to consolidated financial statements 2013 ( continued ) debt maturities as of december 31 , 2015 , excluding premiums and discounts , are as follows ( millions ) : .
Program: subtract(1100, 414)
Answer:
str_answer: 686
exe_answer: 686