Year	% of total fuel combustion
1960	28.492475695831672
1961	29.012604364785147
1962	28.694638346213058
1963	27.29396179054525
1964	29.337304041517655
1965	28.305828697967467
1966	28.197381011679273
1967	28.622348957405098
1968	28.82467246045087
1969	28.93442260496584
1970	30.95298217261755
1971	32.05880143025728
1972	32.16034180933448
1973	32.49702076101123
1974	33.929100825627344
1975	33.60508020020157
1976	35.53547228150498
1977	34.81477577693636
1978	34.82007294128696
1979	35.28761477894008
1980	37.17007779218374
1981	37.471755971594575
1982	38.068284030104884
1983	37.52730043172776
1984	36.58973238300161
1985	35.600568555843
1986	35.71931051420056
1987	35.73140893130496
1988	35.945976048941674
1989	37.5673411235191
1990	38.12852833060678
1991	38.020307929596065
1992	38.026449970691445
1993	37.273743382723225
1994	37.88382185251725
1995	38.12363203295996
1996	37.21717812621546
1997	37.40214923806609
1998	37.631979705367655
1999	37.44888100167604
2000	38.08248149453648
2001	37.7196928625533
2002	38.963371115903215
2003	38.92943399202953
2004	39.335640138408294
2005	39.63676658402825
2006	39.830348228602546
2007	41.446227066861134
2008	39.88799612324335
2009	39.28279120786399
2010	39.268445723987746
2011	40.104773989985596
2012	40.524533217542334
2013	39.07939845903725
2014	38.84390253024891