Year % (national estimate) 1981 55.59114357974492 1983 54.891225141922305 1984 57.28279107142728 1985 56.25203085806982 1986 56.287306497861884 1987 56.543712833427 1988 55.7137142658184 1989 54.277661825551824 1990 54.2027224988257 1991 52.839069866302225 1992 50.8009744627746 1993 49.266471920555276 1994 48.00400476718407 1995 46.642728936577875 1996 46.064279690052416 1997 46.01040662051182 1998 46.7563810356121 1999 47.50514163269288 2000 47.47264714647468 2001 47.21653104844197 2002 47.46020030518144 2003 47.05722848486936 2004 46.77120644644596 2005 46.393910465921316 2006 46.4572830233353 2007 46.42475115441519 2008 46.781160387246004 2009 45.511093058559254 2010 44.509155053492464 2011 43.426444352519944 2012 43.083826673138475 2013 43.118222157167416 2014 42.29243284687295 2015 41.730480168821956 2016 41.50998882371662 2017 41.58725777405359 2018 42.10974951774152 2019 42.21735395407048 2020 40.61324559633057 2021 42.79854334110981 2022 44.094619986568766 2023 45.19622005140466