Year	% of total fuel combustion
1971	9.057971014492756
1972	9.43952802359882
1973	13.59773371104816
1974	7.958477508650519
1975	7.196969696969696
1976	7.806691449814126
1977	6.896551724137931
1978	5.389221556886228
1979	7.458563535911603
1980	12.430939226519335
1981	12.76595744680851
1982	16.350710900473935
1983	24.549549549549543
1984	8.900523560209423
1985	5.172413793103449
1986	4.664723032069971
1987	16.414141414141415
1988	8.488063660477453
1989	4.735376044568246
1990	4.087193460490464
1991	8.638743455497384
1992	16.08961303462322
1993	8.731808731808732
1994	8.163265306122451
1995	6.605504587155962
1996	15.162907268170425
1997	18.867924528301884
1998	16.12121212121212
1999	17.142857142857142
2000	31.55893536121673
2001	29.519230769230763
2002	31.996353691886963
2003	33.13807531380753
2004	36.14947197400487
2005	34.65272591486184
2006	28.86247877758914
2007	31.7092034029389
2008	33.25082508250826
2009	35.55363321799308
2010	27.500000000000004
2011	35.31015678254942
2012	40.53549190535492
2013	29.694323144104807
2014	40.800477897252094