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	28.210033918353993
1972	28.58844500012672
1973	29.254305147073456
1974	29.451784393313936
1975	28.691148940637195
1976	29.00505178825385
1977	28.975567281189345
1978	29.63314339926731
1979	30.49451758003673
1980	31.936727997155582
1981	32.220800397391045
1982	32.45208212922984
1983	33.064013972207455
1984	33.19180256337718
1985	34.6918884047944
1986	35.67808744910922
1987	35.94400679167469
1988	36.24189267073081
1989	37.643056955991234
1990	45.29655889955388
1991	45.78474068078765
1992	46.99982481751826
1993	47.19979507003714
1994	47.57191419363265
1995	46.35288347092005
1996	48.159261319241566
1997	47.74132979898388
1998	48.61641399244281
1999	49.156647986652516
2000	50.011132858472756
2001	50.3983108080284
2002	50.803653593583874
2003	51.66448033079092
2004	49.90834015666424
2005	49.89534750098075
2006	50.57172615048613
2007	50.12408211320418
2008	49.48138266354713
2009	49.46187512537048
2010	50.12997571977063
2011	50.730955942135466
2012	51.15641065197762
2013	51.286429130714694
2014	50.97105668035095