Year	% of total fuel combustion
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	0
1998	0
1999	0
2000	0
2001	0
2002	0
2003	0
2004	0
2005	1.1347517730496457
2006	1.5471167369901548
2007	1.6172506738544479
2008	1.5831134564643796
2009	1.3333333333333335
2010	1.239669421487603
2011	1.5714285714285718
2012	1.536098310291858
2013	1.7793594306049825
2014	1.736111111111111