Year % (national estimate) 1980 63.072059215662854 1981 61.53323792971904 1983 59.877018299720724 1984 60.75037614414216 1985 61.15755504758764 1986 60.21737912187865 1987 59.99361389350286 1988 59.976806821538396 1989 59.91617082968296 1990 59.87248735430103 1991 60.28468388046336 1992 59.31717113286617 1993 58.58795806530738 1994 58.36747962089909 1995 57.52677866090639 1996 57.13236953956066 1997 56.74617458406702 1998 56.708665995548586 1999 56.56039627019885 2000 56.443906585597674 2001 56.12663183342249 2002 55.25573412355668 2003 54.44198639903905 2004 54.15727084173719 2005 53.91332454095574 2006 53.68542107389079 2007 53.48913591961426 2008 53.29798835086516 2009 52.08501756315188 2010 51.34620464319957 2011 51.202721012875976 2012 51.05818896452505 2013 50.99038113025455 2014 50.99941009898962 2015 50.86414195461648 2016 50.78591648242304 2017 50.798275867480534 2018 50.89510581232248 2019 51.07789643183622 2020 48.68821066462161 2021 50.553430375838644 2022 51.203770511352566 2023 51.66272396577119