Year	% of total fuel combustion
1971	1.6129032258064515
1972	1.111111111111111
1973	1.5570934256055369
1974	1.7699115044247788
1975	1.6147635524798163
1976	1.626898047722343
1977	1.1246485473289598
1978	1.8456375838926171
1979	1.6355140186915886
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	0
2006	0
2007	0
2008	0
2009	0
2010	0
2011	0
2012	0
2013	0
2014	0