table of contents respect to the mainline american and the mainline us airways dispatchers , flight simulator engineers and flight crew training instructors , all of whom are now represented by the twu , a rival organization , the national association of airline professionals ( naap ) , filed single carrier applications seeking to represent those employees .the nmb will have to determine that a single transportation system exists and will certify a post-merger representative of the combined employee groups before the process for negotiating new jcbas can begin .the merger had no impact on the cbas that cover the employees of our wholly-owned subsidiary airlines which are not being merged ( envoy , piedmont and psa ) .for those employees , the rla provides that cbas do not expire , but instead become amendable as of a stated date .in 2014 , envoy pilots ratified a new 10 year collective bargaining agreement , piedmont pilots ratified a new 10 year collective bargaining agreement and piedmont flight attendants ratified a new five-year collective bargaining agreement .with the exception of the passenger service employees who are now engaged in traditional rla negotiations that are expected to result in a jcba and the us airways flight simulator engineers and flight crew training instructors , other union-represented american mainline employees are covered by agreements that are not currently amendable .until those agreements become amendable , negotiations for jcbas will be conducted outside the traditional rla bargaining process described above , and , in the meantime , no self-help will be permissible .the piedmont mechanics and stock clerks and the psa and piedmont dispatchers also have agreements that are now amendable and are engaged in traditional rla negotiations .none of the unions representing our employees presently may lawfully engage in concerted refusals to work , such as strikes , slow-downs , sick-outs or other similar activity , against us .nonetheless , there is a risk that disgruntled employees , either with or without union involvement , could engage in one or more concerted refusals to work that could individually or collectively harm the operation of our airline and impair our financial performance .for more discussion , see part i , item 1a .risk factors 2013 201cunion disputes , employee strikes and other labor-related disruptions may adversely affect our operations . 201d aircraft fuel our operations and financial results are significantly affected by the availability and price of jet fuel .based on our 2015 forecasted mainline and regional fuel consumption , we estimate that , as of december 31 , 2014 , a one cent per gallon increase in aviation fuel price would increase our 2015 annual fuel expense by $ 43 million .the following table shows annual aircraft fuel consumption and costs , including taxes , for our mainline operations for 2012 through 2014 ( gallons and aircraft fuel expense in millions ) .year gallons average price per gallon aircraft fuel expense percent of total mainline operating expenses .
[['year', 'gallons', 'average price per gallon', 'aircraft fuel expense', 'percent of total mainline operating expenses'], ['2014', '3644', '$ 2.91', '$ 10592', '33.2% ( 33.2 % )'], ['2013 ( a )', '3608', '3.08', '11109', '35.4'], ['2012 ( a )', '3512', '3.19', '11194', '35.8']]
( a ) represents 201ccombined 201d financial data , which includes the financial results of american and us airways group each on a standalone basis .total combined fuel expenses for our wholly-owned and third-party regional carriers operating under capacity purchase agreements of american and us airways group , each on a standalone basis , were $ 2.0 billion , $ 2.1 billion and $ 2.1 billion for the years ended december 31 , 2014 , 2013 and 2012 , respectively. .

Question: what were total mainline operating expenses in 2014?
Answer: 31903