Year	% of total fuel combustion
1971	33.231190507236924
1972	33.48410973388945
1973	34.013355065986644
1974	33.05899803818364
1975	32.88636460690951
1976	32.529800318882394
1977	32.61183261183261
1978	33.005710850616175
1979	32.786260511673994
1980	34.22305851743443
1981	33.889687426254476
1982	34.68444858579388
1983	35.15952870111855
1984	37.16125066170318
1985	37.65500227228462
1986	40.03560120350971
1987	39.64730382382914
1988	40.659432971648584
1989	39.737445026729524
1990	39.71756631912366
1991	37.86857407502701
1992	39.06431923226193
1993	41.76747571209599
1994	41.8238639274553
1995	42.21167773837471
1996	41.93560813999403
1997	43.67937141705891
1998	43.08042834358624
1999	43.02486793843563
2000	43.19068452809112
2001	43.65465240471219
2002	44.1557051085959
2003	44.9179550272001
2004	45.416238653277716
2005	44.97781837160752
2006	44.78262482379998
2007	43.23704668556643
2008	44.531545565817304
2009	44.81421303571904
2010	45.026247795595296
2011	45.50794713233899
2012	46.13853011338257
2013	46.32706694711596
2014	46.9346792599208