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	0.42194092827004215
1999	0.4149377593360996
2000	0
2001	0
2002	0
2003	0
2004	0
2005	0
2006	0
2007	0
2008	0
2009	3.643724696356275
2010	0.7782101167315176
2011	0.7782101167315176
2012	0.7407407407407407
2013	1.2658227848101267
2014	1.282051282051282