Year	% of total fuel combustion
1960	23.136049192928517
1961	22.440944881889767
1962	22.573189522342066
1963	19.804058782365296
1964	19.189189189189186
1965	19.389027431421447
1966	19.192477876106192
1967	18.794133623030966
1968	19.579702716555612
1969	20.40441176470588
1970	20.008354218880534
1971	20.61765985210961
1972	21.019108280254777
1973	21.575342465753423
1974	17.100044072278536
1975	14.364406779661016
1976	2.407261247040252
1977	2.4830699774266356
1978	2.5480059084194995
1979	2.3619312261201815
1980	2.3503488799118624
1981	2.5530243519245857
1982	2.5904605263157916
1983	2.4590163934426226
1984	2.4750499001996014
1985	2.30973116243847
1986	2.0868394479973076
1987	2.248821182444686
1988	2.2719076812116836
1989	2.2517534145441127
1990	5.061908230152949
1991	7.1290944123314075
1992	6.100519930675911
1993	5.504587155963302
1994	5.481158517595765
1995	5.573248407643312
1996	5.96415327564895
1997	5.687481676927588
1998	5.594405594405594
1999	5.186777747917226
2000	5.6793222466269215
2001	5.809002433090024
2002	6.09230769230769
2003	6.046776953793496
2004	6.323777403035413
2005	6.291678747463032
2006	5.867418899858956
2007	5.4121565362198165
2008	5.184135977337112
2009	5.971404541631623
2010	5.82756785524215
2011	5.913235700469743
2012	6.408808582721626
2013	5.840455840455841
2014	5.267629566694987