Year	% of total fuel combustion
1960	2.2423918846769886
1961	1.9007391763463568
1962	2.0697167755991286
1963	2.519975414874001
1964	2.2080185938407904
1965	2.2328548644338118
1966	2.465596330275229
1967	2.4670109007458403
1968	2.5288620120945575
1969	2.460276781137878
1970	2.771493212669683
1971	3.2826747720364744
1972	3.726708074534161
1973	3.9013195639701665
1974	4.252657911194497
1975	6.677140612725845
1976	6.5297138664710195
1977	7.109737248840804
1978	7.491166077738516
1979	9.132075471698114
1980	10.209003215434084
1981	13.580246913580247
1982	14.58966565349544
1983	15.276273022751893
1984	14.257425742574256
1985	15.004840271055178
1986	16.083916083916087
1987	19.10828025477707
1988	19.148936170212767
1989	20.790216368767638
1990	24.39478584729981
1991	28.049866429207476
1992	31.53070577451879
1993	30.95450490633363
1994	34.10852713178294
1995	40.75425790754258
1996	41.44578313253012
1997	46.794871794871796
1998	53.65168539325842
1999	57.04697986577181
2000	60.17369727047146
2001	58.573072497123135
2002	56.623931623931625
2003	59.45121951219512
2004	60.819234194122885
2005	62.7177700348432
2006	61.027457927369355
2007	61.92703461178672
2008	63.18267419962336
2009	61.370407149950346
2010	61.408450704225345
2011	66.03235014272121
2012	64.14728682170544
2013	66.32548618219039
2014	66.8108108108108