Year	% of total fuel combustion
1971	38.599728629579374
1972	39.22050745487837
1973	39.651634454784066
1974	42.75184275184275
1975	44.374729554305496
1976	45.19441513109831
1977	45.470113349098916
1978	39.619516562220234
1979	42.226816822101
1980	43.26075145233418
1981	44.92372645079061
1982	48.48213559046146
1983	50.664096870155454
1984	51.7620355990921
1985	51.9145285814552
1986	52.746865203761764
1987	54.69913830874835
1988	52.567459451596484
1989	53.954488442931364
1990	54.32858525791731
1991	55.61795780827689
1992	57.139813960093726
1993	59.390333020148255
1994	59.78279430347323
1995	59.7313237221494
1996	60.040625892658774
1997	60.236256247160384
1998	60.89372266225321
1999	60.80009870145892
2000	62.21576286068974
2001	65.58138271873132
2002	64.37565858798736
2003	64.41777489458319
2004	64.12688107218216
2005	62.10858615166778
2006	61.120368890816536
2007	61.212517718896514
2008	62.71567891972993
2009	57.58676011145824
2010	62.2617037921522
2011	60.74873440136664
2012	59.66931854709095
2013	58.37268225267763
2014	59.086376897226636