Year	% (national estimate)
1960	60.19723865877712
1966	62.091230993543014
1970	55.06710996182736
1978	74.65911474722049
1980	67.17029449423816
1983	72.70425163268027
1986	77.23250201126308
1987	76.84210526315789
1988	80.80042547533573
1989	79.69562955254943
1990	79.5505617977528
1991	79.46757679180887
1992	80.09459459459461
1994	81.94276501410721
1995	84.27976909652303
1996	83.67374727668846
1997	84.12655489453759
2003	85.12649800266313
2004	85.38461538461537
2009	85.89991705833563
2010	86.2116991643454
2011	86.73637864611997
2012	84.87208008898776
2013	86.06329816768461
2014	89.36955558836557
2015	90.205153308709
2016	89.23230021489248
2017	88.19105365185325
2018	87.38282053542565
2019	89.61439198421132