Year	% of total fuel combustion
1971	36.7816091954023
1972	39.63133640552996
1973	39.647577092511014
1974	43.93063583815029
1975	42.168674698795186
1976	40.20618556701031
1977	39.81042654028437
1978	39.91031390134529
1979	40.32921810699588
1980	40.07782101167315
1981	43.87351778656127
1982	44.357976653696504
1983	43.12977099236642
1984	41.605839416058394
1985	42.7536231884058
1986	41.254125412541256
1987	41.78272980501393
1988	40.273972602739725
1989	43.30708661417323
1990	45.24421593830334
1991	41.21621621621621
1992	44.63157894736842
1993	45.54655870445344
1994	46.10894941634241
1995	42.77227722772277
1996	42.42990654205608
1997	44.05850091407678
1998	45.43889845094664
1999	46.62273476112026
2000	46.82539682539683
2001	45.88045234248788
2002	47.3186119873817
2003	50.14245014245014
2004	47.90159189580317
2005	49.50354609929079
2006	50.07032348804501
2007	50.40431266846361
2008	51.31926121372031
2009	52.400000000000006
2010	52.20385674931129
2011	52.142857142857146
2012	53.14900153609832
2013	49.288256227758005
2014	50