Year % of total energy use 1990 2.602437629638412 1991 3.3152301863971556 1992 3.8729737244512057 1993 4.674958106938128 1994 16.816669802419685 1995 17.17537699405965 1996 14.302845409664734 1997 8.251923602943442 1998 7.4082003923206905 1999 7.681564250698959 2000 5.663692096368577 2001 6.322356734059882 2002 6.4713853405791095 2003 5.630641696800347 2004 6.211224667602935 2005 6.281177275213756 2006 5.546282644769997 2007 4.268639799580927 2008 4.729006860310209 2009 5.212127312234719 2010 6.43491630649094 2011 3.727759492898519 2012 4.273651273401499 2013 6.0406936221297665 2014 4.2738713585159935