Year	% of total fuel combustion
1990	34.13421008261676
1991	34.69454028820784
1992	35.14798526090574
1993	35.06751757306696
1994	31.084139066035792
1995	34.863945578231295
1996	33.346823148522866
1997	34.68396752109537
1998	33.64260096678622
1999	31.069887834339944
2000	18.964285714285715
2001	25.430245331380448
2002	17.43748431880907
2003	19.400549002151497
2004	22.921931562051775
2005	24.48849512397221
2006	15.832996009946221
2007	20.850472781665687
2008	29.33895066018068
2009	25.994079921065616
2010	25.989416074901623
2011	29.49192964524509
2012	27.242013428559208
2013	28.04525758305248
2014	18.740220841342932