Year	% of total fuel combustion
1960	20.33180015977476
1961	20.22248082249387
1962	20.75496732104979
1963	20.65439873236791
1964	19.465002706138527
1965	19.21483146067416
1966	18.71121512151215
1967	18.41851000802857
1968	18.070310334185926
1969	18.074099913164165
1970	19.87936730403444
1971	19.338003662323974
1972	19.161515421223537
1973	18.199971871851236
1974	17.56339471422792
1975	17.84513973836394
1976	17.863143644446154
1977	17.074275447259986
1978	17.132185008505598
1979	16.39616331166782
1980	15.602460971801673
1981	15.183102611674038
1982	15.483566128907094
1983	15.101213695731138
1984	15.517355416264465
1985	15.681185086095837
1986	15.727317306836664
1987	15.356053965735251
1988	14.996894618082706
1989	14.287250461198912
1990	13.636552447632795
1991	14.056742782444722
1992	13.733335213372722
1993	13.950730174034783
1994	13.299077677208523
1995	13.320015182014732
1996	13.808493062044978
1997	13.118407995722373
1998	12.473351699163803
1999	12.596765052520398
2000	12.289987230408864
2001	12.365648362538293
2002	12.23190824099993
2003	12.384644161233094
2004	12.089794992056888
2005	11.913910174149391
2006	11.325031054115106
2007	10.790174378058557
2008	11.355811722138071
2009	11.88025354273487
2010	11.58914563520502
2011	10.981210724939851
2012	10.784372671161243
2013	11.358308924115256
2014	10.911581529443621