Year	% of total electricity output
1990	49.25488918898204
1991	51.84223164683871
1992	46.573614327957635
1993	46.42244277915365
1994	44.12560914853124
1995	43.878660369513696
1996	43.27607224278931
1997	42.61634478007429
1998	46.336278701353386
1999	45.91930849816182
2000	46.406537453740974
2001	48.44198043392628
2002	48.056614006137146
2003	49.92593965523777
2004	47.195918102123436
2005	52.67541968669569
2006	50.74518437624912
2007	51.32347235412715
2008	47.80554480618158
2009	48.16007942464269
2010	46.99040151568455
2011	44.44989568937189
2012	45.94719037932217
2013	43.64742374429078
2014	41.849852574652225
2015	40.589644378929115