Year	% of total fuel combustion
1960	30.54633813706235
1961	29.990863623091485
1962	28.842767518206195
1963	28.275207730760876
1964	28.89020955110148
1965	29.40324990661188
1966	29.0638276448331
1967	29.138390139987827
1968	29.01514685835572
1969	28.947110824576978
1970	28.00810630365552
1971	27.905780055448208
1972	27.105505055663365
1973	26.819074999032022
1974	27.052453652678036
1975	25.93293494375825
1976	25.173237099757436
1977	25.22490164269777
1978	24.32822803560633
1979	24.27328136578375
1980	23.36277195662415
1981	22.87415798484671
1982	22.100011477607676
1983	22.133779132464383
1984	22.171262813351362
1985	21.475639145895478
1986	20.43930036996467
1987	20.381911715742135
1988	20.756720782209133
1989	20.575170614447917
1990	17.752880374668774
1991	16.823897539068216
1992	16.34538627968047
1993	15.525238824134231
1994	15.276885677669975
1995	16.505207728346303
1996	15.778086111286493
1997	15.939060708002154
1998	15.341215946313012
1999	14.979085567832877
2000	15.402864395125073
2001	15.023190669351958
2002	14.852045380547311
2003	14.784917001230012
2004	14.65643706264227
2005	14.039155193674574
2006	13.564529028727108
2007	14.094099943532163
2008	13.774193842479052
2009	12.728703586322485
2010	13.208325496635885
2011	13.483498169628655
2012	13.072067164418236
2013	13.324258552898952
2014	13.31699626418069