Year	% of total fuel combustion
1960	40.45176515917738
1961	42.50649591685226
1962	42.137351391368725
1963	42.08026698613727
1964	43.374333743337424
1965	44.21975591453059
1966	45.596585495979575
1967	46.473865552378854
1968	48.3258615858784
1969	48.49888266347119
1970	47.32277526395173
1971	44.307361423404046
1972	44.865901096242254
1973	45.18806286420625
1974	46.36831275720164
1975	44.46227929373997
1976	45.062980681887
1977	45.50957309372776
1978	46.513883008508714
1979	46.563794056948616
1980	44.51859291170019
1981	46.25562244827346
1982	46.22640225395053
1983	47.71939255476415
1984	48.61528326745718
1985	49.82925550283295
1986	50.14156885734599
1987	48.7730647124818
1988	48.03672213744156
1989	50.444326995169554
1990	54.0013181190854
1991	54.5770895099019
1992	57.11017443745542
1993	57.181737078068
1994	58.70851345862602
1995	56.633204533245305
1996	57.48599435144091
1997	56.97044026033753
1998	57.456179201995546
1999	57.36124067580947
2000	57.66954490116185
2001	57.84230344394372
2002	57.78216737948965
2003	57.9367915686129
2004	56.76604147435831
2005	57.606016279983194
2006	58.0824219852519
2007	56.508352230987896
2008	55.69905944271666
2009	56.41285272999072
2010	56.57320831804201
2011	56.92845649214012
2012	57.46453069075044
2013	57.020876820028406
2014	56.35520639661543