Year	% (national estimate)
1976	92.92
1977	87.62
1978	88.2
1982	84.14
1986	83.64
1988	82.93
1989	81.63
1990	80.762
1991	80.934
1992	80.649
1993	80.265
1994	80.318
1996	80.011
1997	79.957
1998	78.995
1999	78.528
2000	79.383
2001	80.105
2002	79.177
2003	78.911
2004	79.047
2005	77.051
2006	77.046
2007	76.935
2008	77.041
2009	77.264
2010	78.105
2011	78.87
2012	79.877
2013	79.265
2014	79.262
2015	78.699
2016	78.012
2017	78.269
2018	78.501
2019	79.462
2020	77.902
2021	76.303
2022	78.471