Year	% of total fuel combustion
1960	7.8346241101462875
1961	7.366275391860547
1962	7.128903016456409
1963	6.527942925089181
1964	5.7548222541048935
1965	5.951212144097878
1966	5.143033727706163
1967	4.231066825190133
1968	3.5507673121557484
1969	2.996141333131573
1970	10.10650038627083
1971	10.254975621453122
1972	10.195307545973368
1973	10.21895370215611
1974	10.106244848649073
1975	10.345477017244423
1976	10.563082858675676
1977	10.22037191229531
1978	10.587039560390465
1979	10.196296417399644
1980	10.049067487905496
1981	10.873855243722305
1982	11.985900375664734
1983	12.50151364704173
1984	12.554576531245418
1985	12.449038517064155
1986	12.862620103473763
1987	12.653403285614242
1988	13.002626577548101
1989	12.220263403505134
1990	11.731693253891988
1991	11.700282661811908
1992	12.099222158983114
1993	12.918491042236285
1994	11.977611599601904
1995	12.677276953770322
1996	12.567369811186065
1997	12.66957364341085
1998	13.620372075888746
1999	13.689323837095714
2000	12.953454137604709
2001	13.07854199458819
2002	12.981612519572531
2003	12.403793000807926
2004	12.584125900968143
2005	12.644458974075928
2006	11.959495500455978
2007	11.17834289314015
2008	10.945921827592361
2009	12.278053474724986
2010	10.957708981669695
2011	10.498232851799745
2012	9.7169943994507
2013	10.147202342225116
2014	9.977032381817724