Year	% of total fuel combustion
1960	33.872244205765966
1961	34.283848498040925
1962	35.690979896852966
1963	35.58227344992051
1964	36.27099452726929
1965	36.888174347981426
1966	38.64688732635911
1967	38.568298027757486
1968	38.09340912582577
1969	37.93886975005497
1970	38.59351832238932
1971	37.75809151785714
1972	39.95687622127889
1973	38.49860512300279
1974	44.548774126238904
1975	45.43326831986627
1976	46.09632724873543
1977	47.65453524577612
1978	46.52781411900151
1979	46.52447056439355
1980	48.85846957531198
1981	50.41230650528041
1982	51.86953062848051
1983	52.10625433640599
1984	51.77833317312314
1985	52.7367703838292
1986	52.356446370530875
1987	53.334195997239476
1988	53.751609018809944
1989	54.83071841453344
1990	55.00327262926885
1991	55.667062473666064
1992	55.73956014938324
1993	55.457249070631974
1994	55.252054993816834
1995	55.41265113019098
1996	56.09789075175772
1997	56.1390776538893
1998	58.80481778875849
1999	59.05856595511768
2000	58.852703913952794
2001	59.91848224496379
2002	62.69734391564712
2003	60.86549906478489
2004	61.3200600027274
2005	62.10206496020649
2006	62.514906585398165
2007	62.684217318363665
2008	62.05923836389281
2009	63.31750921670623
2010	62.92293474354366
2011	61.551368094992256
2012	60.903149138443254
2013	59.37826268532053
2014	58.35785756327252