Year	% of total electricity output
1990	59.20465285935052
1991	59.29928844077035
1992	57.90874095098806
1993	59.4781128668884
1994	56.880557930796364
1995	56.546687241081166
1996	53.457821172245
1997	51.33195350607554
1998	54.75518610208183
1999	53.431742560557
2000	53.110983546558586
2001	53.54598315816335
2002	52.64117322691899
2003	51.46370812265414
2004	52.71820502509717
2005	52.469109164310254
2006	50.9882196974031
2007	51.27881393231934
2008	48.61744338645736
2009	48.84073149575677
2010	50.84516411531466
2011	55.32391238698174
2012	58.3444288481937
2013	64.94115375009473
2014	66.05673365056883
2015	65.76200869271827