Year	% of total fuel combustion
1960	41.43748780963525
1961	43.18149964961457
1962	42.91018387553041
1963	43.49591720885551
1964	44.43743427970556
1965	45.18246687054027
1966	46.58028213663021
1967	47.86148377479646
1968	49.90684931506849
1969	49.78600543478261
1970	48.719481813652216
1971	26.083207310402525
1972	26.371273266348208
1973	26.90753987545431
1974	26.92086509404177
1975	26.184882533197143
1976	26.61112781371532
1977	26.392868088962327
1978	28.32372961721757
1979	28.98767567904554
1980	30.51257856730664
1981	30.75835577380009
1982	30.54811854297993
1983	30.975244734887646
1984	31.022549205613057
1985	32.66222469762293
1986	32.95122232662415
1987	33.34435536700253
1988	33.82045619599531
1989	35.5249618461823
1990	45.38634942574127
1991	46.145114161068456
1992	47.99023726910824
1993	47.50125651005792
1994	48.304189068940474
1995	46.54836193447738
1996	49.47100332549274
1997	48.779168762977335
1998	49.70333062550772
1999	50.817359992232085
2000	51.792217658650074
2001	51.76371326107793
2002	52.62683618762758
2003	53.480771033983906
2004	51.17213362699947
2005	51.1507704310513
2006	52.23590583665768
2007	51.53057785358621
2008	50.4394416193495
2009	50.43693740290409
2010	51.327615097583795
2011	52.007409768145955
2012	52.28617033477189
2013	52.611630341676985
2014	51.75478498463256