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	0.4385964912280706
2004	0.41152263374485626
2005	0
2006	0
2007	0
2008	2.2646520574109753E-16
2009	2.0700757469890299E-16
2010	-4.6894722537395E-15
2011	1.8533370469837683E-16
2012	-0.2040816326530612
2013	1.658435445484519E-16
2014	1.5110831672271838E-16