Year	% of total fuel combustion
1960	42.2718222781096
1961	44.38752448395359
1962	43.936522974893414
1963	44.53919317809118
1964	45.551745917170436
1965	46.421570762730326
1966	48.00136077564211
1967	49.36276928136819
1968	51.47656034380791
1969	51.2806459863349
1970	50.18024770674947
1971	51.90868914639664
1972	52.77545979505325
1973	53.423913043478265
1974	54.13399747870737
1975	53.68091823788026
1976	54.29942894976413
1977	55.060523649549395
1978	56.705899992503184
1979	57.841085366754484
1980	57.623614816951516
1981	57.318369145434275
1982	57.28977925226489
1983	59.670176328808836
1984	60.257724410601845
1985	60.072436322317955
1986	58.53163019872498
1987	58.3530525319451
1988	57.6231629540623
1989	59.403714092271976
1990	66.39793521445351
1991	64.40555603684773
1992	63.46956290136426
1993	59.412892757043814
1994	60.18187820762928
1995	55.7571758495546
1996	55.17784523741336
1997	55.258018700437916
1998	57.770302739067766
1999	57.727737973387924
2000	59.486984740730506
2001	60.2715527692148
2002	59.43326140021933
2003	60.12960436562075
2004	58.841165571837614
2005	58.51774389421131
2006	58.09548521017125
2007	57.323677171005414
2008	56.539175394405405
2009	55.95527967351418
2010	54.92879901163925
2011	55.92309214431766
2012	55.40645335311374
2013	56.402355519035886
2014	55.608514908256865