Year	% of total fuel combustion
1971	1.7301038062283738
1972	1.2121212121212124
1973	0.9367681498829041
1974	0.7920792079207921
1975	0.9560229445506693
1976	0.8802816901408451
1977	0.7936507936507938
1978	0.8982035928143712
1979	0.8403361344537815
1980	0.9668508287292819
1981	0.9020618556701032
1982	0.85995085995086
1983	0.8274231678486997
1984	0.9237875288683602
1985	0.9890109890109889
1986	0.9211873080859775
1987	1.0395010395010396
1988	1.0869565217391306
1989	1.1695906432748537
1990	1.2172284644194757
1991	1.361867704280156
1992	1.2315270935960592
1993	1.156515034695451
1994	1.2048192771084338
1995	1.1895910780669146
1996	1.2775017743080197
1997	1.7433751743375174
1998	2.075226977950713
1999	1.1046133853151399
2000	1.1363636363636365
2001	1.162079510703364
2002	1.1052937754508434
2003	1.1731843575418994
2004	1.2373453318335206
2005	1.1186770428015567
2006	0.8501118568232663
2007	0.831146106736658
2008	0.8939455505891915
2009	0.9399264405394361
2010	0.8613938919342208
2011	0.8603832616347282
2012	0.8815638175546185
2013	0.884016973125884
2014	0.842034355001684