Year	% of total fuel combustion
1971	2.713178294573644
1972	2.6515151515151514
1973	2.67175572519084
1974	2.9739776951672865
1975	2.67175572519084
1976	5.5762081784386615
1977	4.642857142857143
1978	4.545454545454546
1979	5
1980	5.047318611987382
1981	4.71976401179941
1982	5.32319391634981
1983	4.4692737430167595
1984	4.610951008645533
1985	4.923076923076923
1986	5.000000000000001
1987	4.819277108433735
1988	4.310344827586206
1989	1.5151515151515154
1990	3.3444816053511706
1991	4.294478527607363
1992	3.546099290780142
1993	4.3795620437956195
1994	3.3057851239669422
1995	3.508771929824562
1996	3.4782608695652173
1997	3.4782608695652173
1998	3.149606299212598
1999	3.2
2000	0
2001	1.4084507042253522
2002	1.2987012987012987
2003	1.0638297872340428
2004	0.9900990099009901
2005	0.78125
2006	2.158273381294964
2007	3.896103896103896
2008	3.4883720930232567
2009	3.4482758620689653
2010	3.2085561497326207
2011	2.5641025641025643
2012	0
2013	0
2014	0