Year % (national estimate) 1961 20.4203228252627 1971 27.04908990623276 1975 38.30110797306104 1978 41.82058047493404 1979 44.8087431693989 1980 46.4984984984985 1990 63.63636363636363 1991 63.90996784565917 1992 49.04242424242425 1993 51.55772755039707 1994 52.996960486322195 1995 51.07632093933463 1996 50.87125485771593 1997 51.341140914242544 1998 55.65379825653798 1999 56.47924863561366 2000 56.36132315521628 2001 56.25790139064476 2002 57.605559926567004 2003 58.08087210039295 2004 56.96218866950574 2005 57.45501285347044 2006 58.71124775813477 2007 57.87481070166582 2008 58.11923786109404 2009 58.745833847673126 2010 59.73521939511548 2011 59.37902454574434 2012 60.15134009623808 2013 62.13583545323226 2014 60.6453360157852 2015 59.83525492543529 2016 60.152290826352264 2017 59.03962824319091 2018 59.20383118826699 2019 59.358857684863565 2020 59.96272158843047 2021 59.119374031689 2022 59.67982704483451