Year % of total population ages 15+ (national estimate) 1965 68.08 1975 65.42 1992 57.17 1997 51.8 2000 50.179 2001 51.373 2002 50.821 2003 49.922 2004 50.551 2005 49.689 2006 51.293 2007 52.596 2008 53.808 2009 53.021 2010 53.394 2011 52.512 2012 53.079 2013 53.9 2014 54.143 2015 54.068 2016 53.331 2017 55.355 2018 55.323 2019 56.582 2020 55.547 2021 55.258 2022 56.57 2023 55.655