Year	% of total fuel combustion
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	2.3255813953488373
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	2.6548672566371696
1990	2.1978021978021998
1991	3.738317757009346
1992	2.7027027027027026
1993	3.333333333333334
1994	2.586206896551724
1995	1.5267175572519076
1996	2.127659574468085
1997	1.9736842105263146
1998	1.8518518518518516
1999	1.3157894736842108
2000	1.3698630136986305
2001	0.6756756756756753
2002	1.449275362318841
2003	1.4388489208633088
2004	1.3986013986013979
2005	1.7341040462427755
2006	1.6666666666666674
2007	1.0309278350515458
2008	1.5
2009	1.4563106796116503
2010	1.1278195488721803
2011	1.6722408026755853
2012	1.5772870662460563
2013	1.7699115044247788
2014	1.7191977077363894