Year	% of total fuel combustion
1960	0.16017084890549935
1961	0.15839493136219596
1962	0.16339869281045769
1963	0.18438844499078075
1964	0.11621150493898777
1965	0.15948963317384268
1966	0.17201834862385207
1967	0.17211703958691926
1968	0.16492578339747127
1969	0.20502306509482335
1970	0.2262443438914029
1971	0.24316109422492424
1972	0.2484472049689443
1973	0.22948938611589234
1974	0.18761726078799268
1975	0.2356637863315006
1976	0.3668378576669115
1977	0.5409582689335399
1978	0.3533568904593627
1979	0.3773584905660364
1980	0.4019292604501612
1981	0.18993352326685678
1982	0.4052684903748737
1983	0.21668472372697503
1984	0.0990099009900991
1985	0.19361084220716163
1986	0.19980019980019997
1987	0.21231422505307873
1988	0.20263424518743686
1989	0.5644402634054567
1990	0.18621973929236516
1991	0.17809439002671432
1992	0.5499541704857933
1993	0.5352363960749336
1994	0.5813953488372077
1995	0.36496350364963265
1996	0.6024096385542174
1997	0.8974358974358982
1998	1.2640449438202228
1999	1.2080536912751687
2000	0.7444168734491308
2001	0.8055235903337177
2002	0.6410256410256393
2003	0.5081300813008134
2004	0.5342831700801429
2005	0.43554006968641157
2006	0.44286979627989365
2007	0.4677268475210497
2008	0.4708097928436911
2009	0.6951340615690169
2010	0.6572769953051649
2011	0.38058991436726963
2012	0.48449612403100817
2013	0.6141248720573189
2014	0.648648648648648