Year	% of total fuel combustion
1960	20.34560135371259
1961	20.232809052119084
1962	20.762767178063747
1963	20.675552024278975
1964	19.48226447752957
1965	19.22604954453305
1966	18.719982785826996
1967	18.438110888391982
1968	18.095930137919268
1969	18.097988742871923
1970	19.894454141695146
1971	18.615555637509285
1972	18.432397432843633
1973	17.565715284064737
1974	16.947898722761703
1975	17.173454800959462
1976	17.137039224934703
1977	16.512285990662754
1978	16.480943552375354
1979	15.885459307563517
1980	15.11822795431458
1981	14.848474588724976
1982	15.043773110594701
1983	14.81157955425048
1984	15.12373391522087
1985	15.348561417508176
1986	15.237551457062576
1987	14.92587849174499
1988	14.70635172944006
1989	14.118404429400542
1990	13.062377974055513
1991	13.1180994975983
1992	12.637935064725701
1993	12.85674156881419
1994	12.408826838825002
1995	12.441500461008395
1996	12.495705971538491
1997	12.239945172556235
1998	11.461488161997696
1999	11.733562835829698
2000	11.376437885805071
2001	11.303042977312742
2002	11.088938561974329
2003	10.976542479466707
2004	10.661539833834548
2005	10.318905527954875
2006	9.862386434002484
2007	9.471572780965612
2008	9.63677070309138
2009	9.615836272724872
2010	9.204829307486438
2011	8.80571413211674
2012	8.632349977761335
2013	8.80433247119665
2014	8.595320151668526