Year	% of total fuel combustion
1971	0.4464285714285714
1972	0.8097165991902834
1973	0.5780346820809249
1974	1
1975	0.4056795131845842
1976	0.8620689655172413
1977	0.7407407407407408
1978	0.7832898172323759
1979	0.4830917874396135
1980	2.8653295128939824
1981	0.1179245283018868
1982	1.4115092290988056
1983	0.31380753138075307
1984	0.2816901408450704
1985	1.7790262172284645
1986	0.4389815627743635
1987	1.0318142734307822
1988	0.41528239202657813
1989	1.71473109898675
1990	0.7240547063555913
1991	0.5826656955571741
1992	0.6920415224913495
1993	0.7203667321545515
1994	0.809968847352025
1995	0.7724301841948902
1996	0.7941009642654567
1997	0.7824726134585288
1998	0.7835455435847208
1999	0.532150776053215
2000	0.611764705882353
2001	0.5340453938584779
2002	0.527306967984934
2003	0.5026929982046678
2004	0.45366169799092687
2005	0.48192771084337344
2006	0.494148244473342
2007	0.43971302939134455
2008	0.51524259338772
2009	0.4968203497615262
2010	0.4728546409807356
2011	0.4783926008611067
2012	0.4376058723884811
2013	0.45335897788157714
2014	0.43808787527380494