Year	% of total fuel combustion
1971	30.004755111745123
1972	27.228682170542633
1973	26.55
1974	26.294416243654823
1975	27.235534774985393
1976	28.172163219675795
1977	27.58435993572576
1978	27.502579979360164
1979	30.504364694471388
1980	29.81308411214953
1981	29.121653358384215
1982	27.475516866158873
1983	27.301420305102575
1984	28.550222662048487
1985	27.166156982670742
1986	24.777448071216618
1987	24.34146341463415
1988	27.500000000000004
1989	32.4
1990	36.051647978253484
1991	29.511677282377917
1992	24.28082191780822
1993	23.126614987080103
1994	27.09620476610768
1995	27.199136535348078
1996	32.42424242424243
1997	31.88992310805342
1998	37.180511182108624
1999	40.23185100722159
2000	34.04649249125695
2001	31.375910844406345
2002	33.22083948534065
2003	35.349794238683124
2004	39.133695855991
2005	38.257993384785
2006	37.477542220625224
2007	41.80145892800507
2008	43.36190046609533
2009	42.000311575011686
2010	40.03499052339991
2011	43.12084993359894
2012	47.86324786324786
2013	46.88452627728325
2014	43.01543332014246