Year	% of total fuel combustion
1971	15.734720416124837
1972	17.01298701298701
1973	16.984615384615388
1974	16.418764302059497
1975	15.852989577619308
1976	16.639654240950836
1977	18.59185918591859
1978	19.94550408719346
1979	20.948410630536735
1980	22.16772927905836
1981	20.668549905838045
1982	21.65242165242165
1983	21.2718064153067
1984	23.614846691769767
1985	21.10803324099723
1986	21.221532091097306
1987	19.530876017233126
1988	19.943555973659453
1989	20.673575129533678
1990	20.794148380355278
1991	19.05018888289261
1992	20.82687338501292
1993	20.479520479520477
1994	18.597857838364167
1995	19.2274678111588
1996	21.19205298013245
1997	21.456692913385826
1998	19.786972552232687
1999	18.39851024208566
2000	18.11292156119742
2001	17.75585696670777
2002	19.161442006269596
2003	19.581825492561318
2004	23.922114047287902
2005	25.89098532494759
2006	24.803711634546747
2007	25.461015852474926
2008	28.267045454545446
2009	29.609976120987003
2010	34.99634947675833
2011	36.092265943012215
2012	34.56818181818182
2013	29.393398751115075
2014	34.42142707679431