Year	% of total fuel combustion
1971	21.545770951881114
1972	23.0822354441139
1973	23.88448651810881
1974	26.285770478906485
1975	26.914751531340674
1976	28.395380903136854
1977	27.45496066988074
1978	25.025064295366374
1979	26.942693064535554
1980	31.024349286314028
1981	32.09426627793975
1982	33.556719476886045
1983	35.274223034734916
1984	34.484868713840676
1985	38.093717570048696
1986	39.82311665529675
1987	42.353340115293314
1988	42.114618580545674
1989	43.014845073229054
1990	43.74728983239381
1991	45.28882286113782
1992	46.791116184592646
1993	49.40466613032985
1994	48.78320101184036
1995	51.61796292109428
1996	52.461650642756844
1997	51.534630011396075
1998	52.72557811476648
1999	53.738525145406555
2000	55.21427608822604
2001	55.86708203530634
2002	54.92646115695413
2003	56.26402197387457
2004	56.887782391784256
2005	55.560495748346575
2006	55.53305756395995
2007	55.453912933474605
2008	53.62066787070688
2009	52.29103742721751
2010	51.50289162370002
2011	51.76420685370168
2012	53.442672384909194
2013	52.3179987692042
2014	53.60529195363599