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	12.656492735081788
1972	13.318813871670299
1973	13.495699702596255
1974	13.7207488299532
1975	12.499089518537401
1976	12.58388101003113
1977	12.295938357058901
1978	11.028665651953323
1979	10.433171479683109
1980	11.952995899381849
1981	11.57155510565608
1982	12.445165554954631
1983	12.764963503649636
1984	11.929341592108285
1985	12.467490247074123
1986	12.372093023255815
1987	13.77277599142551
1988	13.82150570036663
1989	12.794404529666458
1990	10.749418380992509
1991	10.334916371923377
1992	9.31169177048501
1993	10.255350716791067
1994	10.693946968330456
1995	11.5903591502334
1996	11.806337778547967
1997	12.114472431583017
1998	11.633361713493931
1999	12.501304959681967
2000	12.152253260061896
2001	12.082845823839728
2002	11.551716421250504
2003	11.587522694547047
2004	11.39568480889419
2005	11.232121871941708
2006	11.251983962810572
2007	11.19026362583282
2008	12.319309913124025
2009	11.948405419797647
2010	11.41231505575861
2011	11.527356133350764
2012	11.287647033478395
2013	10.86990615619723
2014	11.619173678736882