Year	% of total fuel combustion
1960	27.63521319517267
1961	28.01719266521629
1962	28.325452912366334
1963	29.12799198570915
1964	29.13855263322609
1965	30.136186712489092
1966	30.743309928658036
1967	29.02243311327311
1968	30.026736046965123
1969	31.365905009598116
1970	32.48665218634706
1971	33.00000699612181
1972	34.30645970059576
1973	35.551646570932085
1974	36.05383576522531
1975	36.282454299340756
1976	36.58943984193559
1977	37.60790851491527
1978	37.18583273062692
1979	37.49195203517142
1980	39.08198819133262
1981	39.78151864834518
1982	40.1305434681974
1983	41.18638896845969
1984	40.89968561171933
1985	41.53401349240637
1986	41.55821531548232
1987	42.042501014601626
1988	41.97049157979315
1989	43.39039734086484
1990	44.97058792907787
1991	45.744415181054116
1992	47.06993859957412
1993	47.159066814483644
1994	46.99029744675938
1995	47.76570119727666
1996	47.87639250599452
1997	48.933020046177745
1998	49.311908815914386
1999	48.6297339639156
2000	48.11099060014461
2001	48.460520165419595
2002	48.24281727286685
2003	48.2556802481571
2004	48.20176518161679
2005	48.942087975490466
2006	48.605413395314955
2007	49.05484834308267
2008	49.336311284159656
2009	48.610023301372884
2010	48.797187234082344
2011	48.22743078210275
2012	46.95234782608696
2013	46.6308196669913
2014	45.99040610794383