Year % of total 1995 100 1997 99.7 2000 100 2002 98 2003 99 2004 100 2005 100 2006 97.9 2007 100 2008 100 2010 98.5 2012 98.7 2014 99.1 2015 99.1 2017 100 2018 100 2019 100