Year Percent 2001 71.3 2002 71.3 2003 72.7 2004 71.9 2005 69.5 2006 66.8 2007 65.2 2008 63.1 2009 64.4 2010 65.4 2011 65.2 2012 69.3 2013 68.5 2014 65