Year % of total population ages 15+ (national estimate) 1965 62.97 1970 57.38 1975 53.87 1980 60.51 1983 55.05 1985 62.52 1988 60.49 1995 67.96 1996 54.45 1997 55.08 2003 66.34 2005 69.62 2006 77.9 2007 77.4 2008 69.3 2009 76.42 2010 76.87 2011 77.1 2015 75.94 2016 73.84