Year	% of total fuel combustion
1960	12.69143694233586
1961	13.131427097772477
1962	13.048384926981658
1963	13.02328824431739
1964	13.040818521605852
1965	13.189043840455538
1966	13.766073745887347
1967	13.769508872877257
1968	13.738779013626123
1969	13.279090848791704
1970	12.548034764084457
1971	13.079605574290726
1972	13.35658970587612
1973	13.443840846861136
1974	13.303443430516129
1975	14.553902393194514
1976	14.36457501222086
1977	15.183602649650956
1978	15.549329284517974
1979	15.63324885503072
1980	16.134932394887944
1981	16.670029051000643
1982	17.4015085909359
1983	17.813002624227547
1984	18.133909359870902
1985	18.242005207569
1986	19.00581509093104
1987	19.626094957522042
1988	20.808049139684258
1989	21.12699999595245
1990	21.752758914245142
1991	22.130735704798884
1992	23.394653797666553
1993	24.167338800476564
1994	24.343924068286043
1995	24.268539976825025
1996	24.23222136225951
1997	24.83550735297041
1998	25.460289621315628
1999	26.224194025436265
2000	26.157129988642147
2001	26.0943790156068
2002	26.296361668981714
2003	26.01255291417668
2004	26.37501168989058
2005	26.259484636766587
2006	26.60386349196745
2007	27.037307131342594
2008	26.837551390473813
2009	27.934016791123483
2010	26.966375078433543
2011	27.75567597228891
2012	26.89101172383847
2013	27.330441082915105
2014	29.131991846352363