Year % of total electricity output 1990 66.2021259331386 1991 65.0624738446822 1992 72.3963235146879 1993 74.067080648615 1994 70.8027096006601 1995 70.5063612309254 1996 66.8047933699182 1997 67.9159558229326 1998 69.810409586836 1999 70.6789505307431 2000 72.5440090857467 2001 69.1568277465734 2002 69.0129476493263 2003 60.7828287174897 2004 64.2022341318525 2005 63.6267774900368 2006 65.5155251581415 2007 68.6870289567632 2008 69.2308884377567 2009 71.1396947946197 2010 66.2113227544381 2011 65.6314234326824 2012 74.5291806141755 2013 78.0247869868319 2014 81.0568683458842 2015 76.4907792691417