Year	% of total fuel combustion
1960	19.7376267143709
1961	19.68312004875076
1962	21.64058283864004
1963	16.21488417939872
1964	21.672661870503596
1965	22.81964436917866
1966	24.844036697247702
1967	22.718052738336713
1968	23.26748196926936
1969	26.795895096921324
1970	26.2936695560809
1971	30.79154779749528
1972	31.340098526640787
1973	32.26598648776837
1974	32.749314132340274
1975	32.18047899198592
1976	32.212636496048404
1977	32.554688582866554
1978	30.596242636522852
1979	31.40132547864506
1980	32.977909501326806
1981	33.25959467524717
1982	34.369121266136645
1983	35.11073284250998
1984	36.19677790563866
1985	37.306296477712955
1986	39.33033698200039
1987	39.720736779560305
1988	39.85659894135414
1989	40.53741908443161
1990	40.000828620553946
1991	40.76645232991982
1992	41.465973432895694
1993	42.64872184031188
1994	42.41730720933277
1995	43.11998864204875
1996	43.31119758894632
1997	43.831815572927695
1998	44.88833805756846
1999	44.91192304931448
2000	45.54355240318761
2001	46.743545425083724
2002	46.36562203726305
2003	46.68410613884542
2004	46.69222868554189
2005	46.382554044733915
2006	46.14355657153795
2007	46.18658822854662
2008	46.39540096101668
2009	46.15524912891324
2010	46.11056389376715
2011	46.51739257318974
2012	47.252554645157446
2013	46.995299242328684
2014	47.839295244012206