Year	% of total fuel combustion
1960	29.059829059829063
1961	31.30434782608696
1962	29.032258064516125
1963	29.92125984251969
1964	31.007751937984494
1965	30
1966	29.333333333333332
1967	32.3943661971831
1968	32.21476510067114
1969	37.59398496240601
1970	38.63636363636363
1971	36.42857142857143
1972	34.66666666666667
1973	32.33532934131737
1974	28.915662650602407
1975	27.95031055900621
1976	23.270440251572325
1977	21.472392638036812
1978	18.181818181818183
1979	16.39344262295082
1980	12
1981	10.344827586206897
1982	7.051282051282051
1983	5.031446540880503
1984	3.5502958579881656
1985	3.6809815950920246
1986	2.9411764705882355
1987	2.873563218390805
1988	2.73224043715847
1989	3.296703296703297
1990	2.6315789473684212
1991	2.13903743315508
1992	2.105263157894737
1993	2.0618556701030926
1994	1.9512195121951224
1995	2.0408163265306123
1996	1.7937219730941705
1997	1.4218009478672986
1998	1.9047619047619047
1999	1.4634146341463417
2000	1.3888888888888888
2001	0.9523809523809523
2002	0.9090909090909091
2003	0.9132420091324203
2004	0.881057268722467
2005	0.8968609865470852
2006	0.4405286343612335
2007	0.4310344827586208
2008	0.4716981132075472
2009	0.4807692307692308
2010	0.5128205128205128
2011	0.53475935828877
2012	1.075268817204301
2013	0.4926108374384237
2014	0.49019607843137253