Year	% of total fuel combustion
1960	24.543659394114524
1961	22.69394951744617
1962	22.666898924356573
1963	22.3087455074448
1964	21.992619926199257
1965	21.351554168806032
1966	19.458099919972565
1967	18.510373139799135
1968	17.38582235920426
1969	18.913754574602457
1970	20.45940170940171
1971	14.402189852380486
1972	14.75181000949208
1973	14.633586438283594
1974	14.924554183813445
1975	14.666731520664108
1976	13.866347726034034
1977	13.035084408703602
1978	12.683866209590407
1979	12.252991084074079
1980	13.182863334830985
1981	13.293197702581136
1982	14.671094717643696
1983	13.178336245128346
1984	13.026350461133067
1985	14.36555949198716
1986	14.83541840769336
1987	15.797388585205166
1988	15.847927718431317
1989	14.47903735296648
1990	10.718328974048669
1991	10.624449598013685
1992	9.807664872576357
1993	10.72263441406647
1994	10.916773456170127
1995	11.697183873452296
1996	11.832540727169306
1997	12.106462447563164
1998	11.566139553341436
1999	12.42498650740038
2000	11.960858825764774
2001	11.98763441049946
2002	11.693688446654061
2003	11.722621929428264
2004	11.59699610142384
2005	11.550052144704942
2006	11.690127594138389
2007	11.456769618959404
2008	12.482215031288954
2009	12.322843938466171
2010	11.977564799989603
2011	11.853570986508231
2012	11.73705964384312
2013	11.36345418225775
2014	11.943763532773009