Year	% of total electricity output
1990	97.520184544406
1991	94.8757763975155
1992	82.8379478827361
1993	89.9226384364821
1994	90.1465798045603
1995	82.7494365908625
1996	90.7122032486464
1997	96.9524148993049
1998	91.8529466100129
1999	97.8471997410165
2000	99.1472756178639
2001	98.5174203113417
2002	98.3787375415282
2003	97.8934657185026
2004	99.1965916007304
2005	96.7191283292978
2006	93.8714499252616
2007	92.0220994475138
2008	92.8541270846527
2009	95.15574650913
2010	93.3110716894501
2011	91.2225386493084
2012	91.8419500688028
2013	88.314606741573
2014	89.7915239307037
2015	99.0011098779134