Year	% of total fuel combustion
2000	53.84615384615385
2001	56.25
2002	53.73134328358209
2003	53.42465753424658
2004	51.948051948051955
2005	54.79452054794521
2006	56.16438356164384
2007	61.24999999999999
2008	59.523809523809526
2009	60.747663551401864
2010	58.82352941176471
2011	55.79710144927537
2012	55.61497326203209
2013	61.79775280898877
2014	59.183673469387756