Year	% of total fuel combustion
1960	32.91592128801431
1961	33.94271785496649
1962	33.027522935779814
1963	31.789058649581076
1964	32.05935251798561
1965	33.19220999153259
1966	32.80733944954128
1967	30.493576741041245
1968	29.570398243963623
1969	26.68187001140251
1970	26.976622012083006
1971	17.955628252135156
1972	18.082481131346437
1973	18.334538361129848
1974	18.561653400363074
1975	17.981440951728832
1976	17.771528216372527
1977	17.269204167444308
1978	17.074026987692275
1979	17.099080560707243
1980	17.25257490258218
1981	17.548094506619854
1982	17.064187628670457
1983	16.623838412381637
1984	16.14929038015448
1985	16.23059938694467
1986	16.15626312954137
1987	15.810651345443292
1988	15.692995734773785
1989	15.875049335976346
1990	13.963560587541961
1991	14.162656027290245
1992	14.26508485819041
1993	14.185286623204343
1994	14.101601280731511
1995	14.01272621595819
1996	15.022285145592038
1997	14.879723276544894
1998	15.048539304529662
1999	15.402780564454133
2000	15.92415521974303
2001	15.851399499649586
2002	15.831238318205756
2003	15.379183559175525
2004	15.351131746952989
2005	14.813949648197893
2006	14.40516311928404
2007	14.339191868499272
2008	14.742463606746668
2009	14.570032612618174
2010	14.483063225377615
2011	14.342018318124808
2012	14.793610861375429
2013	14.971967380224259
2014	15.072515348340604