Year	% of total fuel combustion
1971	3.846153846153847
1972	3.448275862068966
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	1.8867924528301876
1983	0
1984	0
1985	1.6393442622950833
1986	1.31578947368421
1987	1.234567901234569
1988	1.111111111111112
1989	0.9900990099009896
1990	-4.486353817181398E-16
1991	-4.163336342344337E-16
1992	-0.7575757575757576
1993	5.900419986315671E-16
1994	0.6622516556291393
1995	5.595882180570345E-16
1996	0.6211180124223613
1997	0.6172839506172849
1998	0.5586592178770944
1999	0.45454545454545403
2000	0.4115226337448555
2001	0.3906249999999996
2002	0.3831417624521069
2003	6.308085367188389E-16
2004	-3.7575237746790047E-16
2005	0.3378378378378378
2006	0.3030303030303025
2007	0.2949852507374634
2008	0.28818443804034605
2009	0.2923976608187137
2010	0.27322404371584647
2011	0.2747252747252742
2012	0.268096514745308
2013	-5.435164937786341E-16
2014	0.25252525252525226