Year	% of total fuel combustion
1971	1.4678899082568806
1972	1.4718614718614718
1973	2.3306627822286963
1974	2.5396825396825395
1975	4.242928452579036
1976	2.196836555360282
1977	4.381846635367763
1978	7.453416149068324
1979	6.8885448916408665
1980	2.2463206816421373
1981	1.239067055393586
1982	1.6679904686258935
1983	2.6294165981922766
1984	2.4227234753550544
1985	2.738515901060071
1986	4.088888888888889
1987	2.7801179443976403
1988	2.5416997617156474
1989	2.30381569474442
1990	0.726552179656539
1991	0.9320905459387485
1992	0.5600497822028625
1993	0.6892230576441105
1994	0.12338062924120907
1995	0.12070006035002986
1996	0.11587485515643109
1997	0.11068068622025427
1998	0.15839493136219646
1999	0.15608740894901152
2000	0.6557377049180326
2001	0.5201560468140443
2002	1.4516798009124845
2003	1.343784994400896
2004	1.6812865497076022
2005	1.6966406515100108
2006	2.1113831089351285
2007	2.156411730879816
2008	1.562021439509954
2009	1.6844276383636985
2010	1.711333548595415
2011	1.4039566049776644
2012	1.9404915912031049
2013	1.1476426799007446
2014	1.2666048810627122