Year	% of total electricity output
1990	15.783720049528519
1991	15.068187280409346
1992	14.040953756674993
1993	14.609999338984618
1994	13.355899635810431
1995	14.285315908247835
1996	13.38093687577469
1997	13.140489481289006
1998	13.51205828916193
1999	12.870079704443992
2000	12.802824551606411
2001	13.69274594408399
2002	13.0031051363363
2003	12.397452758881705
2004	12.977180912467972
2005	12.658119934056405
2006	12.865623917550998
2007	12.563212589350956
2008	14.20488823522049
2009	14.513798653309163
2010	15.205908946405428
2011	14.669407037185227
2012	16.825602984794898
2013	17.433317577131515
2014	19.30149217603918
2015	20.41246622245367