Year	% of total fuel combustion
1971	31.967213114754102
1972	31.199999999999996
1973	32.60869565217392
1974	30.612244897959183
1975	41.61490683229813
1976	30.952380952380953
1977	30.76923076923077
1978	38.06818181818182
1979	36.92307692307693
1980	33.8235294117647
1981	34.5
1982	32.64248704663213
1983	35.6020942408377
1984	34.80392156862745
1985	38.20754716981132
1986	38.72549019607843
1987	41.06280193236715
1988	44.67005076142132
1989	43.269230769230774
1990	40.845070422535215
1991	39.43661971830986
1992	40.948275862068975
1993	42.47787610619469
1994	43.34763948497854
1995	41.53225806451613
1996	40.76923076923077
1997	40.41811846689895
1998	38.24451410658307
1999	36.61971830985916
2000	42.61363636363637
2001	43.08093994778068
2002	39.285714285714285
2003	36.74540682414698
2004	35.58558558558558
2005	41.991341991342
2006	41.89189189189189
2007	34.738955823293175
2008	34.2911877394636
2009	39.29236499068901
2010	38.64468864468864
2011	34.542314335060446
2012	37.742504409171076
2013	37.33333333333333
2014	37.101910828025474