Year % (national estimate) 1960 52.10098936797884 1970 47.85395842208338 1980 51.9149507961889 1990 54.44538125659086 1991 56.77942328879727 1992 59.7381362350985 1993 59.00160573189595 1995 58.46461662230568 1996 57.58111840200581 1997 58.51867740408484 1998 58.419820640515866 1999 58.23926002598629 2001 57.469596331965 2002 58.568536069541906 2003 57.558548573273555 2004 56.97076381346622 2005 56.613051041925985 2006 57.15528015311894 2007 56.21335506204116 2008 55.2364468234402 2009 55.19161816135783 2011 53.14085625461637 2012 52.51437691882386 2013 51.129073670308614 2014 50.50970436802351 2015 50.9438286862083 2016 50.847991891657024 2017 50.26987149216795 2018 50.41224806469335 2019 50.887465121198574 2020 46.25366971476725 2021 50.14965296699351 2022 50.272435747333894 2023 49.04428389821698