Year	% of total fuel combustion
1971	18.38006230529595
1972	23.75366568914956
1973	36.12334801762114
1974	33.723653395784545
1975	23.05295950155763
1976	40.43887147335423
1977	38.34808259587021
1978	19.155844155844154
1979	18.152866242038215
1980	27.79291553133515
1981	26.256983240223462
1982	19.02173913043478
1983	19.466666666666665
1984	18.01801801801802
1985	15.326633165829145
1986	18.112244897959183
1987	12.666666666666668
1988	11.187214611872145
1989	14.177215189873419
1990	12.665406427221173
1991	17.970401691331922
1992	14.446952595936796
1993	0
1994	16.775599128540307
1995	10.208816705336428
1996	3.9024390243902447
1997	10.650887573964498
1998	8.874458874458874
1999	12.37721021611002
2000	9.671532846715328
2001	7.475083056478406
2002	6.032171581769437
2003	5.890052356020943
2004	5.721096543504172
2005	8.519269776876268
2006	11.129163281884647
2007	12.226415094339623
2008	10.0418410041841
2009	15.563139931740613
2010	20.240480961923847
2011	12.696148359486447
2012	12.234432234432234
2013	12.71249076127125
2014	13.118440779610193