Year	% of total fuel combustion
1971	31.977946243969672
1972	32.17576187101347
1973	32.62820512820513
1974	33.00283286118981
1975	31.69774288518155
1976	32.74907749077491
1977	32.69581056466302
1978	17.79935275080906
1979	21.13289760348584
1980	12.687427912341409
1981	14.800995024875624
1982	16.049382716049383
1983	17.59530791788856
1984	16.741405082212257
1985	23.77777777777778
1986	23.776223776223777
1987	24.494949494949495
1988	23.121387283236995
1989	22.033898305084744
1990	20.30075187969925
1991	19.56521739130435
1992	18.881118881118883
1993	18.53448275862069
1994	16.34980988593156
1995	15.96958174904943
1996	16.165413533834585
1997	8.365019011406845
1998	8.47145488029466
1999	8.905380333951761
2000	8.9126559714795
2001	8.97887323943662
2002	9.392265193370166
2003	9.375
2004	9.33098591549296
2005	9.015025041736227
2006	9.337860780984721
2007	9.062499999999998
2008	9.320695102685624
2009	9.443507588532885
2010	13.24200913242009
2011	10.545454545454545
2012	8.590308370044053
2013	8.843537414965986
2014	8.421052631578947