Year	% of total fuel combustion
1960	32.91592128801431
1961	33.94271785496649
1962	33.027522935779814
1963	31.789058649581076
1964	32.05935251798561
1965	33.19220999153259
1966	32.80733944954128
1967	30.493576741041245
1968	29.570398243963623
1969	26.68187001140251
1970	26.976622012083006
1971	15.52590697249383
1972	15.069525883732618
1973	15.625753556788041
1974	15.47581903276131
1975	15.90064826280137
1976	16.049809754410237
1977	16.64490009141962
1978	15.60755961440893
1979	14.490161001788907
1980	13.672807393353326
1981	13.691003416424145
1982	13.743164473288864
1983	13.891970802919705
1984	13.896535902729983
1985	13.291070654529692
1986	13.834625322997416
1987	14.566890772678555
1988	16.844960072321832
1989	16.253509064090974
1990	12.02361543272716
1991	12.415583995776169
1992	12.165833160713756
1993	11.68372692310195
1994	11.507864928639531
1995	11.54577498332857
1996	11.733476168345765
1997	11.854647948218021
1998	12.99352264569874
1999	12.680032237723982
2000	12.322094931695885
2001	12.694541946343167
2002	12.983118568760604
2003	12.928848682151129
2004	13.772337552212553
2005	13.874881598547347
2006	13.913314929179109
2007	14.345952646219
2008	14.758422555188494
2009	14.964400528568332
2010	14.822046585601692
2011	14.380480150413671
2012	14.450931391557873
2013	15.194088533403361
2014	15.536730641958965