Year	% of total fuel combustion
1960	37.43444055944056
1961	36.10051604218084
1962	33.22778129617902
1963	32.766526557126475
1964	33.95987710103018
1965	32.34312416555407
1966	32.52920649370354
1967	31.545440076396623
1968	32.49716553287982
1969	31.340232528427244
1970	27.01849345963013
1971	27.724945135332845
1972	26.64962259556854
1973	29.510355560876327
1974	29.929393305439326
1975	30.350588533097074
1976	27.184805406665113
1977	25.50983468082539
1978	26.731141199226304
1979	26.5892344198826
1980	26.446846353810365
1981	24.331267946199187
1982	23.503142573602386
1983	23.49408553230209
1984	23.269159570529432
1985	22.151790303237963
1986	20.487967914438503
1987	20.651611791070508
1988	20.528967254408062
1989	20.560924767860524
1990	22.800614675374565
1991	21.382818387339864
1992	23.849748382458664
1993	25.902527075812277
1994	25.523012552301257
1995	26.001405481377372
1996	24.439102564102562
1997	25.062211162460006
1998	24.733438210103127
1999	25.43218677597576
2000	26.226669232249378
2001	23.83186705767351
2002	23.83842215057842
2003	22.619488699518342
2004	23.484413845859628
2005	22.2041148910165
2006	20.87534863763141
2007	21.414276184122752
2008	19.725197950628786
2009	15.008597396217146
2010	17.680278019113814
2011	19.33050447901933
2012	18.886629384850025
2013	18.5077004779607
2014	17.39711384286478