Year % (national estimate) 1961 5.616104628798564 1975 14.094791953706256 1979 8.661212829502661 2000 18.608169440242058 2001 17.862595419847327 2002 19.158878504672895 2003 17.72151898734177 2005 18.167701863354036 2006 18.858954041204438 2007 22.826086956521735 2008 22.1875 2009 22.99382716049383 2010 23.149606299212596 2011 23.40764331210191 2012 23.00163132137031 2013 21.85430463576159 2014 21.105527638190953 2017 26.957728062762104 2018 23.82809949729059 2019 21.87484678618706 2020 23.838898719176637 2021 22.750259442897853 2022 22.716836524008524