Year	% of total fuel combustion
1960	31.967213114754095
1961	32.49097472924188
1962	30.9576837416481
1963	30.218068535825545
1964	23.353819139596137
1965	21.88235294117647
1966	21.144452198185622
1967	20.10081915563957
1968	19.158878504672895
1969	18.636127017178552
1970	21.008403361344534
1971	19.51316839584996
1972	19.62681409813407
1973	18.386714116251486
1974	15.7470551766894
1975	15.04398826979472
1976	18.748390419778524
1977	19.80099502487562
1978	19.971870604781998
1979	19.84851860102473
1980	21.13299402522682
1981	21.602865457801656
1982	21.431679721496952
1983	21.912512716174977
1984	22.24188790560472
1985	21.408915795266925
1986	21.90143435086429
1987	20.55137844611529
1988	21.01801096319499
1989	20.625
1990	21.5450643776824
1991	22.622950819672127
1992	22.498618021006084
1993	22.820370882922774
1994	22.44483552186273
1995	21.834574676597413
1996	22.478084521784638
1997	22.958656330749353
1998	24.037628419358832
1999	24.173655648741985
2000	21.675380768356444
2001	21.93118756936737
2002	22.171795439450964
2003	22.342917997870074
2004	22.867222578576012
2005	22.875748345762005
2006	23.66436537440255
2007	23.34626378113516
2008	23.50635593220339
2009	27.480323689169715
2010	26.348597458643013
2011	23.901667275161252
2012	21.3006230529595
2013	23.66090869502105
2014	24.802671523983