Year	% of total electricity output
1990	14.657444846498342
1991	15.398984609021124
1992	16.46084572544237
1993	18.363618991584392
1994	20.057029501512076
1995	20.300534115439973
1996	19.75620255556837
1997	19.757746152039378
1998	20.638721730047727
1999	20.191793621632623
2000	19.104884625486683
2001	18.89159122942516
2002	18.685967545358242
2003	17.984682598370615
2004	19.91966608839724
2005	19.074974136706953
2006	18.43789997932591
2007	17.23940115530539
2008	16.256349635610395
2009	17.990861085349557
2010	18.552764272754516
2011	17.255908245518572
2012	17.443905443580636
2013	19.145794740938157
2014	17.473233119199513
2015	18.618018837828394