Year	% of total fuel combustion
1960	39.23371647509579
1961	41.47933284989123
1962	37.697841726618705
1963	37.45632424877708
1964	35.27027027027027
1965	35.08403361344538
1966	36.36942675159236
1967	34.295816146140254
1968	36.28556092324208
1969	33.84932920536636
1970	32.41308793456033
1971	29.898336414048053
1972	29.312762973352037
1973	29.586935638808836
1974	28.950863213811424
1975	29.754020813623463
1976	29.67535436671239
1977	30.281090289608176
1978	26.724137931034488
1979	29.400887573964496
1980	27.73271533410583
1981	29.739198131568706
1982	30.906212900672735
1983	32.56369426751592
1984	28.87550200803213
1985	28.43100189035917
1986	29.060451565914054
1987	26.872852233676976
1988	26.690391459074732
1989	26.47964420116319
1990	32.2152108933909
1991	30.729166666666668
1992	28.1868310087577
1993	27.879961277831562
1994	27.184769038701628
1995	25.957707631014397
1996	25.309005297233668
1997	23.806801943412403
1998	23.35106382978723
1999	22.071611253196927
2000	21.332353661523392
2001	21.182495344506517
2002	21.269011406844104
2003	22.087205146533236
2004	21.967909391222275
2005	21.858047016274863
2006	21.74297721742977
2007	21.507311586051745
2008	23.138056312443233
2009	24.924012158054712
2010	25.527587083651156
2011	23.367404883588872
2012	22.919585318016253
2013	24.062772449869225
2014	22.002362669816893