Year	% of total fuel combustion
1960	24.612775579423403
1961	23.650413582934263
1962	23.976423534364805
1963	24.513116057233706
1964	24.41970183053406
1965	24.240800285816363
1966	23.820956954210256
1967	23.853583313042776
1968	24.082040251958826
1969	24.671992963424465
1970	22.932994422085713
1971	23.27706473214285
1972	23.138602520045822
1973	24.137712401724578
1974	22.697501883730364
1975	22.685984954026193
1976	23.103144930723555
1977	22.83701699760094
1978	24.705636087707365
1979	24.485763501874555
1980	23.97697591177324
1981	24.31402806577615
1982	24.133089990172678
1983	25.28496382198434
1984	25.579159857733348
1985	24.878491937315466
1986	25.38371253159985
1987	24.663561076604555
1988	24.656396628327034
1989	24.06904958515198
1990	23.878643206406654
1991	23.204504539012525
1992	23.414689350786528
1993	23.486988847583643
1994	23.5760529570088
1995	23.665673734010863
1996	23.66481882098432
1997	23.543577225044537
1998	22.04447189623224
1999	22.12491637778994
2000	22.408126680609502
2001	21.816262498900393
2002	21.810263316237357
2003	21.651646545372103
2004	21.5927996727124
2005	21.32716713271671
2006	21.526434344772756
2007	21.566653761775715
2008	21.864341582254138
2009	21.461037321347405
2010	22.485495712892128
2011	23.293753226639133
2012	23.480327572399183
2013	24.09949885153477
2014	24.744502113542726