Year	% of total energy
1990	4.668865565159582
1991	4.806484334758618
1992	5.153353270202069
1993	4.880450938333142
1994	4.67253422514833
1995	4.328507986879786
1996	4.1493598842676445
1997	3.990822200352585
1998	4.0719943975053985
1999	3.532026271867043
2000	6.912395601530568
2001	6.437122608411881
2002	5.981188239128315
2003	6.314423537503086
2004	6.211134692771827
2005	6.192095870747853
2006	5.953125940953106
2007	5.877520624856772
2008	5.775515410975465
2009	8.602981734645642
2010	8.784085996955548
2011	8.620876143370158
2012	8.817999601067323
2013	9.56564530888413
2014	8.360688913951543
2015	9.150437765819099