Year	% of total fuel combustion
1971	36.56664340544312
1972	35.92462834958811
1973	35.426500337154415
1974	33.46153846153846
1975	30.554481478617276
1976	29.217036828788306
1977	27.437884050227087
1978	29.16945950886601
1979	29.94541484716157
1980	33.17949481415315
1981	32.6663113522942
1982	32.29132797621813
1983	34.14925637393768
1984	35.05329562758321
1985	34.59132786746682
1986	36.50578675203152
1987	35.339364712446695
1988	36.27151051625239
1989	37.61444557477111
1990	36.6984601241094
1991	36.86106148792716
1992	40.780716962138584
1993	42.92004510551468
1994	44.357197438802665
1995	43.06080735820133
1996	43.21665183427272
1997	46.20223994100567
1998	43.37436459683047
1999	39.126396518323915
2000	41.06958446029014
2001	41.42916245288222
2002	41.1968177101349
2003	42.213973401348156
2004	40.884807276259444
2005	39.72113126779295
2006	41.317683017426184
2007	41.12680347311383
2008	41.3247066138183
2009	44.17602854106573
2010	42.34235829511448
2011	41.848816867691745
2012	42.01414456222066
2013	43.16887722049848
2014	44.9354351836324