Year	% of total fuel combustion
1960	28.08621202097775
1961	28.590205607194644
1962	28.893941214123966
1963	29.090187080833047
1964	29.684039508545855
1965	30.08001866324507
1966	30.473787957360134
1967	29.672089472709064
1968	30.16929567952218
1969	31.0628486922676
1970	32.46038823126134
1971	32.94310932996229
1972	33.65064669200018
1973	34.58760617571775
1974	35.22813749735113
1975	35.39732988774793
1976	36.10318151544649
1977	36.756337559041526
1978	36.67946442525058
1979	36.84541831739039
1980	38.202297078298855
1981	38.67538466475702
1982	39.19037478751016
1983	39.62482365261947
1984	39.35895956788506
1985	39.391145255524584
1986	39.3891479674154
1987	39.67192589576548
1988	39.826724287357585
1989	41.0339347825454
1990	43.06404906651319
1991	43.25292794399588
1992	43.97793619853786
1993	43.8239841621741
1994	44.02378592666006
1995	44.19502490766408
1996	43.99464490628586
1997	44.63565525710193
1998	45.21948145698919
1999	44.78425647454118
2000	45.00492663623341
2001	45.19205970164203
2002	45.55941153459869
2003	45.7685371054479
2004	45.77075757155151
2005	46.495947516603216
2006	46.45964053674703
2007	47.510972553334554
2008	47.401927292694474
2009	47.01727694572595
2010	47.2732809927167
2011	47.55407915728741
2012	47.366544476009636
2013	46.766506382745256
2014	46.213574602055836