Year	% of total fuel combustion
1960	21.311475409836063
1961	22.26233453670277
1962	22.38307349665924
1963	22.741433021806852
1964	24.319578577699737
1965	25.960784313725487
1966	29.309141660851363
1967	25.14177693761815
1968	21.49532710280374
1969	25.039042165538778
1970	26.1437908496732
1971	24.740622505985638
1972	24.257083621285418
1973	23.72479240806643
1974	24.333539987600744
1975	23.13782991202346
1976	22.173577131084212
1977	22.33830845771144
1978	22.105016408813878
1979	23.145466696368903
1980	22.08453197610091
1981	19.52093127378554
1982	18.711923411662315
1983	18.41302136317396
1984	18.348082595870206
1985	16.74922032654559
1986	16.734093416697313
1987	15.92314118629908
1988	15.473766640563822
1989	14.44767441860465
1990	13.776824034334764
1991	13.585174625801852
1992	12.672747374239911
1993	12.413506781068365
1994	12.034655475835928
1995	12.58330066640533
1996	13.489467486589035
1997	13.47545219638243
1998	12.860502537442752
1999	11.470152935372473
2000	11.593543987269832
2001	11.465038845726971
2002	10.94753154748727
2003	10.14909478168264
2004	9.39704939063502
2005	9.13769562020796
2006	9.591078066914497
2007	10.422621478154351
2008	9.036016949152541
2009	7.149983372131693
2010	7.9956844881323414
2011	7.022027503955214
2012	7.5674974039460015
2013	8.17244883147046
2014	9.092289010321798