At constant prices, world airlines RASK fell by 51% from US¢17.5 in 1960 to 8.6 cents in 2015, while CASK went 54% down from 17.5 to 8.1.[5] For the world airline industry between 2003 and 2017, CASK excluding fuel was around US¢6, fuel CASK was between US¢1 and US¢3.5, and RASK was between US¢7 and US¢10.[6]