Year	% of total fuel combustion
1960	28.591380649541616
1961	29.156334739925466
1962	29.440348207870176
1963	29.6291032646427
1964	30.235906052939626
1965	30.634906367041204
1966	31.05915391539154
1967	30.330832479720936
1968	30.87584540304737
1969	31.744682851283113
1970	33.01722804175502
1971	33.70886114872279
1972	34.40869392051435
1973	35.311037601169815
1974	36.00079535622214
1975	36.100228799473314
1976	36.83235240463549
1977	37.44080451470486
1978	37.3739307878522
1979	37.48361564604386
1980	38.71305803965105
1981	39.20793492222064
1982	39.709859340326865
1983	40.24621361676591
1984	40.19386149983848
1985	40.30400513800796
1986	40.3354431458232
1987	40.55992175023807
1988	40.68023502602711
1989	41.91238234249386
1990	43.23236536892798
1991	43.53051264498349
1992	44.528556623261245
1993	44.1844155594624
1994	44.33779803495797
1995	44.50829588662288
1996	44.46581277293204
1997	45.195986235647595
1998	45.834185105506194
1999	45.4877055251074
2000	45.761435834763056
2001	46.0246873568448
2002	46.34819764676527
2003	46.62820133251629
2004	46.758831984265065
2005	47.359802995903024
2006	47.40295305344031
2007	48.28414499198819
2008	48.13991942803363
2009	47.706891679115024
2010	47.8538030951597
2011	48.206613780893505
2012	48.0220593935961
2013	47.45735450069187
2014	46.994711775855755