Year	% of total fuel combustion
1960	4.397964951950254
1961	4.407923378319548
1962	4.810019997894958
1963	4.471383147853736
1964	6.0105680317040955
1965	6.368345837799215
1966	6.662665066026411
1967	6.21702783864946
1968	7.005684436933477
1969	7.520340101150774
1970	4.2434512462049
1971	4.352678571428572
1972	3.8609258136244184
1973	5.002536139994928
1974	1.402654610792326
1975	1.3597102256896074
1976	1.3635363976248076
1977	1.3067224746056862
1978	1.3920142341305146
1979	1.4135170736650116
1980	1.4027280642352713
1981	1.4466894922119884
1982	1.5442931349150635
1983	1.4818118743185642
1984	1.6437566086705757
1985	1.503520327049739
1986	1.4761646803900326
1987	1.4665286404416837
1988	1.3702611800855378
1989	1.3762730525736309
1990	1.3052015554614407
1991	1.3061630980196883
1992	1.305217096080577
1993	1.3308550185873604
1994	1.3311995344438787
1995	1.3281934466444716
1996	1.2844780962682534
1997	1.3063271095863294
1998	1.2476837554045705
1999	1.2588943623426379
2000	1.2548550941141319
2001	1.2344954989297132
2002	1.4440846967135614
2003	1.7400668820495384
2004	1.6773489704077458
2005	1.7423101742310172
2006	1.5979859546839799
2007	1.530520067105433
2008	1.536094371073215
2009	1.5100247462249383
2010	1.573650972942445
2011	1.5875064532782657
2012	1.6171949675785995
2013	1.6574441428273123
2014	1.6908341805340046