Year % of total electricity output 1990 23.5043544112079 1991 22.3496478237313 1992 21.2356057620736 1993 21.9369821742405 1994 22.2517442803829 1995 21.9480769230769 1996 20.955749002539 1997 20.5158485657561 1998 19.4104754947114 1999 21.4366012117673 2000 17.7034411271643 2001 18.4325544535434 2002 14.6462607915686 2003 14.0644863053276 2004 12.9981539798024 2005 12.1409513294691 2006 11.7332570814595 2007 13.0593227788922 2008 11.9009462759463 2009 10.0690647482014 2010 10.0479577100193 2011 9.32683633406604 2012 8.87941297956605 2013 8.88188039274026 2014 8.87090779127949 2015 8.25928551410343