operating expenses millions 2014 2013 2012 % (  % ) change 2014 v 2013 % (  % ) change 2013 v 2012 .
[['millions', '2014', '2013', '2012', '% (  % ) change 2014 v 2013', '% (  % ) change 2013 v 2012'], ['compensation and benefits', '$ 5076', '$ 4807', '$ 4685', '6% ( 6 % )', '3% ( 3 % )'], ['fuel', '3539', '3534', '3608', '-', '-2 ( 2 )'], ['purchased services and materials', '2558', '2315', '2143', '10', '8'], ['depreciation', '1904', '1777', '1760', '7', '1'], ['equipment and other rents', '1234', '1235', '1197', '-', '3'], ['other', '924', '849', '788', '9', '8'], ['total', '$ 15235', '$ 14517', '$ 14181', '5% ( 5 % )', '2% ( 2 % )']]
operating expenses increased $ 718 million in 2014 versus 2013 .volume-related expenses , incremental costs associated with operating a slower network , depreciation , wage and benefit inflation , and locomotive and freight car materials contributed to the higher costs .lower fuel price partially offset these increases .in addition , there were approximately $ 35 million of weather related costs in the first quarter of operating expenses increased $ 336 million in 2013 versus 2012 .wage and benefit inflation , new logistics management fees and container costs for our automotive business , locomotive overhauls , property taxes and repairs on jointly owned property contributed to higher expenses during the year .lower fuel prices partially offset the cost increases .compensation and benefits 2013 compensation and benefits include wages , payroll taxes , health and welfare costs , pension costs , other postretirement benefits , and incentive costs .volume-related expenses , including training , and a slower network increased our train and engine work force , which , along with general wage and benefit inflation , drove increased wages .weather-related costs in the first quarter of 2014 also increased costs .general wages and benefits inflation , including increased pension and other postretirement benefits , and higher work force levels drove the increases in 2013 versus 2012 .the impact of ongoing productivity initiatives partially offset these increases .fuel 2013 fuel includes locomotive fuel and gasoline for highway and non-highway vehicles and heavy equipment .volume growth of 7% ( 7 % ) , as measured by gross ton-miles , drove the increase in fuel expense .this was essentially offset by lower locomotive diesel fuel prices , which averaged $ 2.97 per gallon ( including taxes and transportation costs ) in 2014 , compared to $ 3.15 in 2013 , along with a slight improvement in fuel consumption rate , computed as gallons of fuel consumed divided by gross ton-miles .lower locomotive diesel fuel prices , which averaged $ 3.15 per gallon ( including taxes and transportation costs ) in 2013 , compared to $ 3.22 in 2012 , decreased expenses by $ 75 million .volume , as measured by gross ton-miles , decreased 1% ( 1 % ) while the fuel consumption rate , computed as gallons of fuel consumed divided by gross ton-miles , increased 2% ( 2 % ) compared to 2012 .declines in heavier , more fuel-efficient coal shipments drove the variances in gross-ton-miles and the fuel consumption rate .purchased services and materials 2013 expense for purchased services and materials includes the costs of services purchased from outside contractors and other service providers ( including equipment maintenance and contract expenses incurred by our subsidiaries for external transportation services ) ; materials used to maintain the railroad 2019s lines , structures , and equipment ; costs of operating facilities jointly used by uprr and other railroads ; transportation and lodging for train crew employees ; trucking and contracting costs for intermodal containers ; leased automobile maintenance expenses ; and tools and supplies .expenses for purchased services increased 8% ( 8 % ) compared to 2013 primarily due to volume- 2014 operating expenses .

Question: what percentage of total operating expenses was fuel in 2014?
Answer: 23%