Year	% of total energy use
1990	26.14517222928737
1991	27.339949608863257
1992	32.33849956760256
1993	36.764130085320595
1994	48.668508857741585
1995	52.7608814788149
1996	53.654745338636886
1997	47.169030737829345
1998	46.50339943292433
1999	49.59889928832141
2000	52.27755365897475
2001	53.56482585361575
2002	54.43468581453003
2003	54.30070792313029
2004	51.24882124107587
2005	52.94499732276056
2006	51.60361675276799
2007	48.03594172674592
2008	48.855433270329684
2009	53.82243360005553
2010	55.576721062405824
2011	53.806280339347026
2012	50.022787064774136
2013	44.47588787418042
2014	37.48194946916705