Year % of total 1994 95 1995 100 1999 92 2000 97.3 2001 96.6 2002 99.2 2003 98.2 2004 94 2005 96.6 2006 96.8 2007 96.7 2008 96.7 2009 96.7 2010 96.8 2011 96.7 2012 96.8 2013 96.7 2014 96.7 2015 96.3 2016 96.5 2017 96.6 2018 96.4 2019 96.5