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	15.626916429726267
1972	15.884051910033063
1973	16.38707138288975
1974	16.632448405587272
1975	16.07912864793501
1976	15.91519028209371
1977	15.277019461230232
1978	14.902862985685072
1979	15.033762790504994
1980	15.053191927682054
1981	15.586589192234467
1982	15.474632012516361
1983	14.94381455111846
1984	14.541508608112053
1985	14.463720300027674
1986	14.62084052806461
1987	14.295185457085662
1988	14.164774978728111
1989	14.372017854394336
1990	13.566665161785478
1991	13.507674597695468
1992	13.76098850433393
1993	13.494800236528178
1994	13.158417291948112
1995	12.883780117483076
1996	13.852243560008661
1997	13.484606419844557
1998	13.702599478062952
1999	14.24745581146224
2000	14.956435842684005
2001	14.841775017138225
2002	14.738455214688386
2003	14.209622405083898
2004	14.182640250337155
2005	13.608667077908358
2006	13.307599059486117
2007	13.105844841769246
2008	13.407490552894767
2009	13.019842083174733
2010	12.908251525429833
2011	12.755423660681657
2012	13.23096743266321
2013	13.51642555318543
2014	13.67108534391084