Year	% of total fuel combustion
1960	40.45176515917738
1961	42.50649591685226
1962	42.137351391368725
1963	42.08026698613727
1964	43.374333743337424
1965	44.21975591453059
1966	45.596585495979575
1967	46.473865552378854
1968	48.3258615858784
1969	48.49888266347119
1970	47.32277526395173
1971	27.868105151192836
1972	28.242070205767046
1973	28.877281775116888
1974	29.086878543818024
1975	28.334159306454126
1976	28.63012646561876
1977	28.59654393850602
1978	29.238105012634914
1979	30.057522784999254
1980	31.49238941588668
1981	31.786398742539046
1982	32.03414536791659
1983	32.66095626779408
1984	32.83992269797059
1985	34.317375666345306
1986	35.28876091688854
1987	35.622565787591604
1988	35.904712105455914
1989	37.28205448614179
1990	44.75502280910755
1991	45.24597196852762
1992	46.490286355979784
1993	46.709158526749704
1994	47.07962677039946
1995	45.90274834103236
1996	47.62394101203744
1997	47.20702741434676
1998	47.990770965136626
1999	48.49761672767492
2000	49.372633861629204
2001	49.744388013970244
2002	50.135875762044485
2003	50.9259104057844
2004	49.30441555524266
2005	49.330343014756636
2006	50.023457390508334
2007	49.58711969427628
2008	48.97043079059602
2009	49.022317520267
2010	49.67246055506302
2011	50.24118384553462
2012	50.637421846085246
2013	50.801853171774766
2014	50.49155305096362