Year % (national estimate) 1991 50.22 1994 58.53 1997 50.7 1998 51.4 1999 46.06 2000 43.7 2001 44.6 2002 42.13 2003 40.49 2005 38.886 2006 41.945 2007 43.918 2008 43.215 2009 43.302 2010 41.32 2011 40.056 2012 40.456 2013 39.87 2014 39.48 2015 40.445 2016 39.646 2017 41.989 2018 40.808 2019 38.157 2020 37.943 2021 34.633 2022 35.962