Year	% of total fuel combustion
1960	37.04780361757106
1961	35.41014402003757
1962	37.44102137107966
1963	37.71111671288127
1964	42.20343198209402
1965	42.265387315703265
1966	39.11255411255411
1967	41.29419613075383
1968	39.82701812191103
1969	38.19864720541118
1970	36.57306204809147
1971	37.2202166064982
1972	35.360752875566405
1973	35.08803130001779
1974	33.92
1975	30.457913737412124
1976	32.18390804597701
1977	30.45727636849132
1978	29.39694271795733
1979	28.797970187123372
1980	24.12371134020619
1981	25.009458948164966
1982	16.206395348837212
1983	15.518575851393187
1984	15.31819035104186
1985	16.879711569977058
1986	15.814255560967688
1987	16.103678929765888
1988	14.701679171132549
1989	14.27147697827387
1990	12.517166960957427
1991	10.704363458081387
1992	10.612909058036522
1993	11.561795805165541
1994	9.641291998052266
1995	10.277492291880781
1996	9.088370794359905
1997	9.356819650937299
1998	9.61007591442374
1999	9.804637575314953
2000	9.418719211822662
2001	9.419182269774549
2002	9.029779058597503
2003	8.268059181897302
2004	8.882023556671173
2005	9.248554913294797
2006	7.539471350008871
2007	7.556675062972292
2008	7.7524162039893065
2009	7.846481876332623
2010	8.470986869970352
2011	8.018082322150844
2012	8.85147977192506
2013	8.311755567063699
2014	7.563025210084033