Year	% of total fuel combustion
1960	33.30657676459571
1961	32.90834987982025
1962	32.56166797180893
1963	32.4885960466295
1964	31.47948861435151
1965	30.46071328503382
1966	29.596532944695863
1967	29.45076443735961
1968	29.38239956825311
1969	29.624240072435647
1970	28.690623211542515
1971	27.937674555343232
1972	28.549870050023756
1973	23.44968980482999
1974	23.895551056429426
1975	23.06447762777498
1976	23.82176080587963
1977	22.43972902968719
1978	21.697598253275107
1979	20.962561718038444
1980	20.010896084515718
1981	19.474037100499146
1982	21.971524157784174
1983	19.700767870807713
1984	19.350748161298505
1985	19.448464995810163
1986	19.06502800248911
1987	16.978943386710377
1988	16.757694381285017
1989	17.230929280593436
1990	17.431826849733028
1991	17.348668280871667
1992	17.258954785672344
1993	18.20179584120983
1994	17.833029197080293
1995	17.386558552939345
1996	17.985393889633116
1997	17.028258506813813
1998	15.220800660338421
1999	15.66701033011907
2000	16.401573125133194
2001	15.941316446734449
2002	16.45572081267619
2003	16.581174180020966
2004	16.13412153813986
2005	16.21626672647081
2006	15.294207433412193
2007	14.984539047892994
2008	14.93598599981579
2009	15.17705920143283
2010	14.028715413140628
2011	14.823731407349348
2012	13.719285182427399
2013	14.041151963905618
2014	14.52415284787311