Year	% of total fuel combustion
2005	24.242424242424242
2006	20.444444444444446
2007	28.90995260663507
2008	22.878228782287824
2009	36.627906976744185
2010	27.38095238095238
2011	25.590551181102363
2012	26.923076923076927
2013	23.348017621145374
2014	23.423423423423422