Year	% of total population ages 15+ (national estimate)
1960	45.92
1970	44.83
1975	48.3
1981	43.76
1983	43.82
1984	45.67
1989	26.19
1991	27.82
1993	50.8
1995	49.193
1997	41.7
1998	49.72
1999	50.91
2000	50.89
2001	52.98
2002	53.26
2003	48.09
2006	45.81
2007	44.25
2008	44.3
2009	42.94
2010	42.7
2011	43.4