Year	% (national estimate)
1960	30.41331382589612
1970	47.30021598272138
1980	49.36216216216216
1985	55.69699499165276
1991	64.92307692307692
1994	66.60958904109589
1996	69.18714555765597
1997	64.38095238095237
1998	66.6068222621185
1999	76.08318890814557
2000	71.34748685664535
2001	80.1597284313577
2002	79.7200886487143
2003	78.55897100501417
2004	76.79468430088383
2005	78.36227284042818
2006	80.02622647331071
2007	78.9886294700493
2008	77.71166370633512
2009	78.0163147061066
2010	75.59576559302644
2011	78.49192043765613
2012	77.73317740762982
2013	78.52683158144313
2014	78.11146587424525
2015	78.40888095091458
2016	78.04049920469839
2017	79.3073579916725
2018	79.21248233921003
2019	79.76353166986564
2020	79.45671183171795
2021	79.47722899294419
2022	80.07784185811983
2023	81.97216712124968