Year	% of total fuel combustion
1971	8.726842099270106
1972	8.864428898444686
1973	9.145923843598263
1974	9.44273997874431
1975	8.935362863751742
1976	8.792934905211093
1977	8.419668060830883
1978	8.04758159653952
1979	8.23250281387496
1980	8.252329600352764
1981	8.449441705477717
1982	8.490017808604367
1983	8.539218894077754
1984	8.353525563363219
1985	8.542300241344602
1986	8.742896557404054
1987	8.654409575132322
1988	8.655255852090175
1989	8.841926433112821
1990	8.368911917098446
1991	8.387579117949844
1992	8.693112460776897
1993	8.93789323295876
1994	8.62517063950436
1995	8.536328166192135
1996	10.327781293360193
1997	9.769477230094248
1998	9.170821597153434
1999	10.009416779912373
2000	11.85468502348058
2001	11.69335668869155
2002	11.636250675823081
2003	11.143851907456677
2004	10.936020986775084
2005	10.16494802179975
2006	9.675299996169947
2007	9.499457092748571
2008	9.871329218901696
2009	9.726646882636064
2010	9.68383998459936
2011	9.587508886489902
2012	10.228932111425745
2013	10.58072621491586
2014	10.838752644744057