Year	% of total fuel combustion
1960	40.33345558157249
1961	40.760546642899584
1962	38.69113420296264
1963	39.22750613976334
1964	38.5623164928622
1965	37.36611770125533
1966	38.17135000429664
1967	39.40341592494588
1968	38.82397076600297
1969	39.36188595408541
1970	34.908843073777476
1971	40.59364377278126
1972	40.20690957877046
1973	38.75509958936349
1974	38.81136837484912
1975	38.52336278500281
1976	38.73240276072523
1977	38.12050517453078
1978	37.36460796627048
1979	36.71993064943088
1980	36.06206383458621
1981	34.994066388634586
1982	35.63510115327406
1983	35.42874688903972
1984	35.44867271049346
1985	33.7248016530653
1986	33.3897340983048
1987	33.19790294216552
1988	32.474790861303724
1989	31.356935857567407
1990	30.66023118890444
1991	30.151981162898117
1992	29.58990756148773
1993	29.252200016448718
1994	29.163053930919236
1995	30.421131141874806
1996	28.276815690550656
1997	27.61974441861037
1998	27.733716344549332
1999	25.576942124203512
2000	25.03905507385335
2001	25.120889439660683
2002	24.32337204551909
2003	24.39962640341226
2004	26.85734046511977
2005	27.831972280945234
2006	28.06546312970052
2007	28.415528678118154
2008	29.236198492645624
2009	29.414885151981323
2010	28.971109162960424
2011	28.553694800377723
2012	27.78237981554381
2013	27.099323572965936
2014	27.68640911129747