Year Percent 2000 20.08197 2001 17.58377 2002 17.76747 2003 18.98976 2004 20.28891 2005 22.94 2006 23.51044 2007 25.09416 2008 24.84008 2009 24.2764 2010 24.59573 2011 23.0578 2012 23.02803 2013 22.37755 2014 22.09424