Financial report context:
on may 20 , 2015 , aon plc issued $ 600 million of 4.750% ( 4.750 % ) senior notes due may 2045 . the 4.750% ( 4.750 % ) notes due may 2045 are fully and unconditionally guaranteed by aon corporation . we used the proceeds of the issuance for general corporate purposes . on september 30 , 2015 , $ 600 million of 3.50% ( 3.50 % ) senior notes issued by aon corporation matured and were repaid . on november 13 , 2015 , aon plc issued $ 400 million of 2.80% ( 2.80 % ) senior notes due march 2021 . the 2.80% ( 2.80 % ) notes due march 2021 are fully and unconditionally guaranteed by aon corporation . we used the proceeds of the issuance for general corporate purposes . credit facilities as of december 31 , 2015 , we had two committed credit facilities outstanding : our $ 400 million u.s . credit facility expiring in march 2017 ( the "2017 facility" ) and $ 900 million multi-currency u.s . credit facility expiring in february 2020 ( the "2020 facility" ) . the 2020 facility was entered into on february 2 , 2015 and replaced the previous 20ac650 million european credit facility . each of these facilities is intended to support our commercial paper obligations and our general working capital needs . in addition , each of these facilities includes customary representations , warranties and covenants , including financial covenants that require us to maintain specified ratios of adjusted consolidated ebitda to consolidated interest expense and consolidated debt to adjusted consolidated ebitda , tested quarterly . at december 31 , 2015 , we did not have borrowings under either the 2017 facility or the 2020 facility , and we were in compliance with the financial covenants and all other covenants contained therein during the twelve months ended december 31 , 2015 . effective february 2 , 2016 , the 2020 facility terms were extended for 1 year and will expire in february 2021 our total debt-to-ebitda ratio at december 31 , 2015 and 2014 , is calculated as follows: .

Financial table:
years ended december 31,: net income; 2015: 1422; 2014: 1431
years ended december 31,: interest expense; 2015: 273; 2014: 255
years ended december 31,: income taxes; 2015: 267; 2014: 334
years ended december 31,: depreciation of fixed assets; 2015: 229; 2014: 242
years ended december 31,: amortization of intangible assets; 2015: 314; 2014: 352
years ended december 31,: total ebitda; 2015: 2505; 2014: 2614
years ended december 31,: total debt; 2015: 5737; 2014: 5582
years ended december 31,: total debt-to-ebitda ratio; 2015: 2.3; 2014: 2.1

Additional report context:
we use ebitda , as defined by our financial covenants , as a non-gaap measure . this supplemental information related to ebitda represents a measure not in accordance with u.s . gaap and should be viewed in addition to , not instead of , our consolidated financial statements and notes thereto . shelf registration statement on september 3 , 2015 , we filed a shelf registration statement with the sec , registering the offer and sale from time to time of an indeterminate amount of , among other securities , debt securities , preference shares , class a ordinary shares and convertible securities . our ability to access the market as a source of liquidity is dependent on investor demand , market conditions and other factors. .

Question: what was the percent of the change in the interest expense from 2014 to 2015
Answer: 7.1%