Year	% of total energy use
1990	5.170884020971073
1991	6.0434978700210555
1992	5.626835235806861
1993	6.479781971814464
1994	10.525691098386813
1995	9.73656063084109
1996	9.697579590970546
1997	12.584610330931811
1998	14.811914742691922
1999	16.494793802762235
2000	15.080328778467333
2001	14.464826284387536
2002	17.413406296298774
2003	16.862778121959657
2004	16.256579634483533
2005	16.392862006131246
2006	12.194049701930917
2007	12.768234068820005
2008	14.943960794246342
2009	15.518697615879448
2010	20.043756015210615
2011	15.469447379461549
2012	14.397101575995453
2013	16.81110483339594
2014	15.746373934121397