Year	% of total fuel combustion
1971	28.438605356240526
1972	28.143915548883832
1973	29.424729997795897
1974	28.322365609776938
1975	27.198063799396927
1976	28.591460939518058
1977	28.783285239434562
1978	30.409037787300353
1979	31.089017696057734
1980	30.956081691668174
1981	30.772657186911083
1982	27.910262595630293
1983	25.088849009465502
1984	23.804014971078594
1985	24.14228303829419
1986	23.638497652582153
1987	22.531087675114115
1988	23.306605098124862
1989	21.864427631174266
1990	21.744009705793147
1991	19.99029891469108
1992	18.06001019154102
1993	15.44594514190516
1994	15.108298422319285
1995	14.62375365735875
1996	15.308232221557212
1997	15.375321336760928
1998	15.701665825340735
1999	14.731149407441912
2000	14.267705418147896
2001	11.90589515196845
2002	12.340724170449814
2003	13.06134367895209
2004	13.327330031517334
2005	13.938238212916655
2006	13.413078766329132
2007	11.979021369190425
2008	11.20403649433232
2009	14.495578415448477
2010	12.736595773969306
2011	12.573325764222187
2012	12.056258141107024
2013	12.504354435190171
2014	12.967932890640574