Year	% of total energy use
2005	19.67031144520571
2006	16.70410243991554
2007	17.081246325987838
2008	13.711654303880014
2009	19.126589220015617
2010	16.057441618977883
2011	11.822516815127752
2012	13.5375622562581
2013	15.045448258089749
2014	12.95729601843372