Year	% of energy use
1992	19.355382884602886
1993	23.184900088484525
1994	25.531267695766484
1995	26.792515615853997
1996	27.86622896220884
1997	25.121243656749044
1998	28.803322789487684
1999	29.278222949576392
2000	28.265933597121588
2001	28.373512087331314
2002	26.851223370709654
2003	29.670710831407742
2004	35.218204069556336
2005	34.40911441313038
2006	25.860613464408566
2007	26.084767158828566
2008	19.105789902883835
2009	22.20605899393602
2010	21.57739641983091
2011	21.88353653158294
2012	22.536109619858383
2013	22.355470855953566
2014	22.267234318455607