Year	% of total electricity output
1990	67.1551915335441
1991	65.8846653068793
1992	65.65744497027406
1993	67.47715503140851
1994	66.02995493222443
1995	66.17008532366421
1996	66.26759788914158
1997	64.72323220747829
1998	62.79643889030647
1999	62.05638933916778
2000	61.48067636072412
2001	57.87778774487372
2002	58.64132687901932
2003	57.7408097509876
2004	57.757504339045816
2005	58.12017833798636
2006	58.62128912508958
2007	58.46172290197663
2008	57.501654246499236
2009	58.01500450697596
2010	57.74939283395984
2011	58.80998754764108
2012	56.25300250106238
2013	54.10937833282454
2014	53.306594486153664
2015	52.095055465217