Year	% of total fuel combustion
1971	28.06034757145585
1972	27.973230183581997
1973	28.98453261600538
1974	28.127361036157577
1975	26.870966152633397
1976	28.23540263813301
1977	29.37954524532818
1978	32.21366204417052
1979	33.39539096306732
1980	33.77483443708609
1981	33.190539124094244
1982	29.694949775494145
1983	26.444850466391003
1984	24.970500136153216
1985	25.52370699322657
1986	25.340624287992707
1987	24.323633419965063
1988	25.265592871830016
1989	23.214964320398597
1990	22.192601099171522
1991	20.45416457181163
1992	18.217350667006542
1993	14.578700271806275
1994	14.648988474248409
1995	14.309913378248314
1996	15.327546553898658
1997	15.858038166326317
1998	16.28591978627941
1999	14.883687012324073
2000	14.452247691704395
2001	11.53979840111227
2002	12.181017073618507
2003	12.089016511127063
2004	13.073009615640732
2005	14.228155470197962
2006	13.135094662530753
2007	10.916104639280604
2008	10.36601214527067
2009	15.292173651795101
2010	12.92471849338644
2011	11.552401470029146
2012	11.383649341411365
2013	12.373618066710764
2014	12.582024372956536