Year	% (national estimate)
1970	75.146
1980	77.593
1982	83.03
1983	82.77
1984	81.63
1985	81.25
1986	79.8
1987	79.77
1988	80.15
1989	81.05
1990	81.88
1991	75.434
1992	81.94
1993	82.77
1995	81.95
1996	82.8
1997	82.38
1998	80.66
1999	79.93
2000	79.29
2001	79.55
2002	78.84
2003	79.17
2004	78.13
2005	77.23
2011	77.4
2014	78.43
2015	78.29
2016	77.66
2017	77.45
2018	77.94
2019	78.27
2020	77.06
2021	77.26
2022	78.75