Year	% of total fuel combustion
1960	36.417910447761194
1961	36.28655476726077
1962	34.77257745550429
1963	36.837029893924786
1964	36.97878023445615
1965	38.42645381984037
1966	36.239674839386396
1967	33.74387181633385
1968	27.781350482315116
1969	39.006596042374575
1970	39.77637246815141
1971	40.30577956989247
1972	38.06322529011605
1973	39.13012273020885
1974	36.44258817289843
1975	33.27128001027089
1976	31.5105827776167
1977	33.48268345846452
1978	32.61465375479627
1979	30.456184534371246
1980	27.06229860365199
1981	26.47739221871714
1982	23.763825634352635
1983	24.068752660706682
1984	23.563314867662694
1985	23.953757225433524
1986	22.676517031355743
1987	21.892195395845032
1988	23.13972088918308
1989	20.95223715335447
1990	20.256663376110563
1991	20.235775062984267
1992	18.017124831004956
1993	18.46442127516456
1994	19.243004010880092
1995	18.674672393390892
1996	17.862714508580343
1997	18.862643653789064
1998	18.237332893216703
1999	15.665984383291637
2000	16.938929379241017
2001	18.3004433004433
2002	17.253331538565085
2003	18.38373822508676
2004	17.565789473684212
2005	17.006863891136888
2006	13.91248153618907
2007	14.654508851915448
2008	14.869708418095515
2009	13.716894315423357
2010	15.283609435834794
2011	14.75453172205438
2012	13.876516664106898
2013	15.113360840529158
2014	14.27216690374585