Year	% of total fuel combustion
1971	38.64752550056668
1972	39.72652689152234
1973	39.45478528506522
1974	39.212400502723085
1975	36.811631497684
1976	35.54809584442644
1977	36.852246222492646
1978	35.121042830540034
1979	32.623937969149544
1980	33.69435374691407
1981	35.31292827775239
1982	33.97621588656807
1983	33.02185163887291
1984	34.03566710700132
1985	35.46149399447621
1986	35.82227707497686
1987	34.73327788998456
1988	31.58607753230513
1989	29.259168102387395
1990	27.543049501532085
1991	23.576568121382767
1992	21.973240509083
1993	20.52781080724006
1994	18.360425323881692
1995	18.19174553396427
1996	18.01572739187418
1997	17.422226643125356
1998	15.564870608098275
1999	16.89198126934575
2000	13.932964258414216
2001	12.968946329204808
2002	13.577215247974664
2003	13.315204972350442
2004	11.913930770402281
2005	12.65764682739175
2006	11.443332257022924
2007	10.74698795180723
2008	10.350331505279527
2009	9.965533042456117
2010	9.653231663035585
2011	9.135923007183209
2012	8.915813444121893
2013	8.946485371736166
2014	8.12771877916909