Year	% of total electricity output
1990	19.47787955958183
1991	21.013294021136918
1992	20.02438267488969
1993	19.063100636902576
1994	18.502240535108484
1995	18.649589781980765
1996	18.049408544309475
1997	17.818495835534076
1998	18.87967876054065
1999	19.88270255170107
2000	20.59720918673944
2001	21.945705070931076
2002	22.010338072814413
2003	20.63263657177242
2004	20.905092512878433
2005	21.308026329278057
2006	21.571189973636326
2007	20.650044415194046
2008	21.447711081027155
2009	22.69095818931705
2010	23.732982018380437
2011	23.803551837578084
2012	24.091231695530492
2013	24.764098554546138
2014	26.581240781412905
2015	26.616637023783245