Year % (national estimate) 1991 44.74 1994 46.69 1997 43 1998 43.5 1999 38.8 2000 37.6 2001 39.9 2002 35.62 2003 35.29 2005 33.347 2006 35.736 2007 35.981 2008 35.862 2009 34.979 2010 32.364 2011 32.18 2012 33.55 2013 33.676 2014 32.641 2015 33.118 2016 31.699 2017 33.053 2018 32.101 2019 32.192 2020 30.883 2021 28.111 2022 28.418