Year	% of total fuel combustion
1960	35.15624999999999
1961	29.701897018970193
1962	30.490709861838976
1963	30.337504740235115
1964	26.078353779184805
1965	24.76120499632623
1966	23.576937201615863
1967	25.758645024700073
1968	25.07355344883949
1969	25.47085201793722
1970	25.0337199892096
1971	23.001799023387303
1972	22.326644653289307
1973	22.597160809867354
1974	22.733177448687968
1975	21.774632553075666
1976	20.14519056261343
1977	21.010774756285276
1978	20.773067331670823
1979	20.47101449275362
1980	21.70700636942675
1981	24.37703141928494
1982	21.757801316919554
1983	25.26881720430107
1984	22.911261027503894
1985	21.695402298850578
1986	19.827172347575615
1987	17.72056985753562
1988	15.980933266432515
1989	15.762797769893563
1990	16.04514229636899
1991	16.048814183743957
1992	15.248796147672552
1993	15.615976900866215
1994	15.283950617283951
1995	15.649867374005305
1996	14.965664219748994
1997	14.431486880466474
1998	14.000938086303938
1999	14.838108548800372
2000	13.614687649022414
2001	13.926677426792713
2002	12.93330145828353
2003	13.319434792680102
2004	13.069489185457892
2005	12.801822323462414
2006	13.707451701931925
2007	14.13436070310619
2008	13.72093023255814
2009	12.853717026378897
2010	12.877030162412991
2011	13.145780051150894
2012	12.833168805528134
2013	12.803850782190136
2014	13.645998940116588