Year	% of total fuel combustion
1971	4.8358807316462045
1972	4.67479674796748
1973	4.553049289891396
1974	4.836098745447188
1975	4.188779378316905
1976	3.9150630391506303
1977	4.563152156984894
1978	4.460290827740493
1979	5.277044854881268
1980	5.213854307900899
1981	5.235538198681963
1982	4.1898792943361185
1983	4.289255307684018
1984	3.4878682842287705
1985	3.5613397901533497
1986	2.499267792638875
1987	3.4552067381317
1988	3.100228994187071
1989	3.2477341389728096
1990	1.9034065640843194
1991	1.604681895412497
1992	1.2399439072994316
1993	1.0811164984929889
1994	0.8474576271186444
1995	1.0065425264217414
1996	0.8979347500748281
1997	0.7215309003450803
1998	2.724885095206828
1999	2.6123152002296535
2000	2.363015903676518
2001	1.754385964912281
2002	1.6844075330448007
2003	1.4810880981884704
2004	1.7525076073481345
2005	2.069722755970354
2006	2.7871054398925454
2007	3.200462160600809
2008	2.2264598258001342
2009	0.9525163491612165
2010	2.662437925134582
2011	2.1117379721046863
2012	2.746266513497989
2013	2.9123237277743717
2014	2.64732965009208