Year	% of total fuel combustion
1971	12.280701754385968
1972	14.285714285714285
1973	12.85714285714286
1974	11.940298507462686
1975	12.85714285714286
1976	12.820512820512823
1977	8.928571428571429
1978	7.142857142857144
1979	7.4074074074074066
1980	5.925925925925926
1981	6.870229007633586
1982	9.923664122137405
1983	8.799999999999999
1984	7.142857142857144
1985	5.633802816901409
1986	6.122448979591836
1987	6.211180124223603
1988	7.608695652173914
1989	6.557377049180327
1990	7.772020725388601
1991	10.106382978723405
1992	11.11111111111111
1993	5.363984674329503
1994	10.749185667752444
1995	7.4498567335243555
1996	8.115942028985508
1997	7.571801566579634
1998	7.46268656716418
1999	6.9478908188585615
2000	7.926829268292683
2001	7.038123167155424
2002	6.685236768802229
2003	4.31266846361186
2004	5.319148936170214
2005	6.628242074927954
2006	5
2007	2.1447721179624666
2008	2.538071065989848
2009	2.1951219512195124
2010	3.4334763948497855
2011	2.874743326488707
2012	5.158730158730159
2013	2.434077079107505
2014	2.890173410404624