Year	% of total fuel combustion
1965	23.01975356933307
1966	24.066628374497416
1967	24.985695212664506
1968	25.05673222390318
1969	25.440668726149372
1970	25.294217977144807
1971	26.364692218350754
1972	26.48100450740502
1973	26.177931657383713
1974	26.257633032858386
1975	24.262715486536546
1976	24.645583424209377
1977	24.08370158565116
1978	22.916421077449016
1979	23.405275779376495
1980	23.127193513251846
1981	22.060442921815735
1982	21.807992202729043
1983	22.20239612541423
1984	22.17391304347826
1985	21.712423216748153
1986	21.589167092488502
1987	21.079236699102744
1988	21.444877131730898
1989	21.537196876284426
1990	21.391595615103533
1991	18.515600378190985
1992	16.55003498950315
1993	15.461042356632385
1994	14.8030383324501
1995	14.735158194098826
1996	14.891020052310372
1997	12.305212251477702
1998	11.435696473102956
1999	10.952380952380953
2000	10.808782135485082
2001	10.922992900054615
2002	11.166482096714654
2003	10.39098274040155
2004	10.55020882513165
2005	10.836988304093568
2006	10.635155096011816
2007	10.795887281035794
2008	10.72463768115942
2009	8.726264134841049
2010	9.165440403615726
2011	9.442622950819672
2012	8.914177335229967
2013	13.84918679152292
2014	15.590863952333663