Year	% of total fuel combustion
1960	24.8062015503876
1961	23.705057891529556
1962	23.20561252023745
1963	27.057663873829473
1964	24.415467625899282
1965	22.396274343776458
1966	20.954128440366972
1967	23.225152129817445
1968	24.239573534023208
1969	23.603192702394526
1970	23.37798791699501
1971	24.059429666906308
1972	25.01529051987768
1973	23.488151658767773
1974	23.001808318264015
1975	20.576890826765048
1976	21.163941802909854
1977	20.063694267515924
1978	18.677255922223747
1979	17.80639431616341
1980	20.42499650496295
1981	19.018836097835255
1982	20.443413250837843
1983	20.53067595149478
1984	18.65739685434238
1985	19.394066463989937
1986	18.42283502660861
1987	20.523863936011253
1988	20.81647664582567
1989	18.41821946169772
1990	16.998348147565483
1991	16.84316302079307
1992	17.732926193490727
1993	16.25777841356126
1994	14.116371521503435
1995	15.748913186668423
1996	14.177817424918226
1997	14.49645390070922
1998	12.832108535895987
1999	12.521217607785445
2000	12.711190618167361
2001	12.12137810155009
2002	12.557753205627368
2003	13.763864924821295
2004	14.709291095228897
2005	15.662149035570563
2006	15.326486305945222
2007	14.928240479150187
2008	19.460173650434125
2009	18.3348268204309
2010	17.427839324741882
2011	17.574353032058706
2012	20.111011993259986
2013	17.08450704225352
2014	15.157435446582657