Year	% of total electricity output
1990	32.5856049914581
1991	41.8648972965342
1992	40.8453552649319
1993	38.414339882799
1994	35.8122464747924
1995	34.6849971621366
1996	33.8607400110817
1997	34.7024880560898
1998	38.2171927734763
1999	38.2124432842315
2000	38.2155225096761
2001	38.2162721510801
2002	38.2176839173822
2003	36.9005152596116
2004	33.4006179196704
2005	33.000552274948
2006	27.1008221549113
2007	27.0998346244234
2008	27.1009000473709
2009	22.9003387773676
2010	24.4018222885801
2011	21.7614855367315
2012	19.7136487145544
2013	18.4399127514455
2014	17.5913129318855
2015	18.1951250556864