Year Percent 2000-01-01 19.69 2001-01-01 22.41 2002-01-01 24.55 2003-01-01 17.88 2004-01-01 23.20 2005-01-01 22.16 2006-01-01 24.90 2007-01-01 29.39 2008-01-01 22.15 2009-01-01 29.33 2010-01-01 24.35 2011-01-01 18.85 2012-01-01 21.88 2013-01-01 21.84 2014-01-01 23.39 2015-01-01 24.83 2016-01-01 26.26