Year % of total population ages 15+ (national estimate) 1966 73.22 1977 67.2 1992 59.32 1995 67.17 1996 64.8 1997 66.002 1998 65.097 1999 64.941 2000 64.413 2001 63.177 2002 57.77 2003 55.928 2004 55.604 2005 53.938 2006 54.967 2007 54.769 2008 54.509 2009 54.44 2010 54.87 2011 54.111 2012 54.613 2013 54.533 2014 54.87 2015 54.544 2016 53.723 2017 54.939 2018 54.977 2019 55.14 2020 55.062 2021 51.069 2022 51.831 2023 51.471