Year % (national estimate) 1991 58.12 1993 51.109 1994 52.112 1995 50.649 1996 49.444 1997 48.347 1998 49.05 1999 48.278 2000 46.097 2001 43.125 2002 40.063 2003 38.127 2004 35.844 2005 33.864 2006 33.53 2007 31.92 2008 31.143 2009 31.844 2010 30.879 2011 29.929 2012 31.27 2013 31.547 2014 32.199 2015 32.478 2016 31.98 2017 31.652 2018 30.406 2019 29.713 2020 27.305 2021 27.041 2022 27.675 2023 27.77