Year	% of total fuel combustion
1960	28.564071437767844
1961	29.128240160916928
1962	29.415523294560593
1963	29.584789170848296
1964	30.20604688499503
1965	30.60734897635632
1966	31.034858700329934
1967	30.299788524052282
1968	30.84424928344747
1969	31.7233012698139
1970	32.98823454786206
1971	33.338776259450405
1972	34.00999203089561
1973	34.93666715123323
1974	35.58827631434481
1975	35.70420556211265
1976	36.38712283909928
1977	37.03744311227263
1978	37.01653121925101
1979	37.199251999203796
1980	38.52424203899632
1981	38.869540526288354
1982	39.37604016586779
1983	39.89684051471239
1984	39.73571034414297
1985	39.78333869560108
1986	39.79754989581189
1987	39.96394134784949
1988	40.018491964757565
1989	41.21132898387486
1990	42.45646862018213
1991	42.8465794434172
1992	43.58161136744008
1993	43.10496768863709
1994	43.510653106284174
1995	43.61708836973828
1996	43.546281605848215
1997	44.306212275302805
1998	45.0279588010341
1999	44.66770811334074
2000	44.84381822550428
2001	45.192177361613645
2002	45.4167136204266
2003	45.60539917964104
2004	45.62948646941801
2005	46.21585023294584
2006	46.12753017200419
2007	47.16358737608764
2008	46.97475318839414
2009	46.698369029926134
2010	46.840515341556
2011	47.09727753609869
2012	46.95423947038725
2013	46.43028606216189
2014	45.91941915393124