Year % (national estimate) 1960 82.54341610442395 1970 70.27260076910927 1980 71.33941654185455 1990 70.91969104979172 1991 72.86355243471175 1992 74.53886048931632 1993 74.638444188844 1995 72.50651798451726 1996 71.33272986132611 1997 71.95417291320491 1998 71.77103641928622 1999 71.33365763351533 2001 69.6757173264868 2002 70.03050421248221 2003 69.09292683959585 2004 67.98621556654663 2005 66.99880014457246 2006 68.33054457364634 2007 66.58098511620894 2008 65.25833700185237 2009 65.26197153033014 2011 63.33047359793164 2012 62.83745681155048 2013 61.215812642908155 2014 60.727606155972275 2015 61.06301145185186 2016 60.342502461389245 2017 59.54032514200556 2018 59.524344401675 2019 59.73374109058654 2020 54.39187474842025 2021 58.435874656172906 2022 58.593225455924106 2023 56.612274936159096