Year	% of total fuel combustion
1960	17.82982290684271
1961	18.03023454371955
1962	18.754144954997635
1963	18.66185634634306
1964	18.45619417125327
1965	19.65087281795511
1966	20.23730818748043
1967	20.65478404978523
1968	20.139636553456658
1969	19.46033098077391
1970	18.98760330578512
1971	28.84478895584285
1972	27.637857181586508
1973	27.058762133389003
1974	27.292813445893305
1975	27.969703242775907
1976	28.108295329908216
1977	28.7674871613246
1978	27.685521807914338
1979	27.94039382650346
1980	27.90756703522078
1981	26.954033267751743
1982	26.497378151962728
1983	26.43429788300138
1984	26.591956323183805
1985	24.913309407066677
1986	24.712302764266223
1987	24.326948963501405
1988	25.299877123520123
1989	25.515378179215514
1990	21.7103180681064
1991	19.278176820076258
1992	16.271113191918463
1993	16.317826590735397
1994	17.810029738454105
1995	19.926231889549936
1996	19.646907374486606
1997	19.627316603539356
1998	17.940692372035294
1999	16.28737043488193
2000	17.358381502890172
2001	16.11955132755928
2002	15.945531373003005
2003	15.174580329093953
2004	15.331416906220058
2005	14.777316658775034
2006	14.309309309309311
2007	14.253522656313635
2008	13.403823709220251
2009	11.71076683347817
2010	11.33736452455515
2011	11.523846676202446
2012	11.466434018742197
2013	12.008055325725527
2014	12.679224520179952