Year	% of total fuel combustion
1971	15.789473684210526
1972	11.538461538461538
1973	7.692307692307692
1974	8.108108108108109
1975	9.375
1976	12.5
1977	13.793103448275865
1978	14.285714285714285
1979	8.88888888888889
1980	1.9230769230769231
1981	2.272727272727273
1982	1.9607843137254901
1983	1.3698630136986303
1984	1.2658227848101267
1985	3.6363636363636362
1986	1.3513513513513513
1987	1.3333333333333335
1988	2.7027027027027026
1989	0
1990	0
1991	2.6548672566371683
1992	3.508771929824562
1993	3.8461538461538463
1994	4.320987654320988
1995	1.7045454545454544
1996	1.6393442622950818
1997	4.285714285714285
1998	4.09090909090909
1999	1.6611295681063125
2000	0.6451612903225806
2001	0.2985074626865672
2002	0
2003	0
2004	0.37037037037037035
2005	0.32573289902280134
2006	0.4
2007	0.3875968992248062
2008	0.34722222222222227
2009	0.2915451895043732
2010	0
2011	0
2012	0.2012072434607646
2013	0.20576131687242796
2014	1.854974704890388