Year	% of total fuel combustion
1971	68.42105263157896
1972	66.66666666666666
1973	70
1974	68.65671641791045
1975	68.57142857142857
1976	70.51282051282051
1977	61.60714285714285
1978	58.57142857142858
1979	68.88888888888889
1980	80.74074074074075
1981	80.91603053435115
1982	79.38931297709924
1983	80
1984	81.42857142857143
1985	83.80281690140845
1986	82.31292517006803
1987	83.22981366459628
1988	81.52173913043478
1989	85.24590163934425
1990	83.9378238341969
1991	81.38297872340426
1992	81.33333333333333
1993	87.35632183908045
1994	83.71335504885994
1995	83.95415472779369
1996	85.79710144927536
1997	86.6840731070496
1998	86.56716417910448
1999	86.35235732009924
2000	85.36585365853658
2001	87.68328445747801
2002	88.02228412256268
2003	90.8355795148248
2004	89.62765957446808
2005	87.89625360230546
2006	89.72222222222221
2007	92.76139410187668
2008	92.89340101522842
2009	92.92682926829269
2010	92.48927038626609
2011	93.01848049281315
2012	90.87301587301587
2013	93.30628803245435
2014	93.06358381502889