Year	% (national estimate)
1960	38.19948009303598
1966	43.30806340454859
1970	51.27656730383639
1975	61.21164437450825
1979	62.1505376344086
1980	55.94661782022765
1981	55.78812698663923
1982	57.89087709005574
1983	58.15283077800563
1984	56.38430611396091
1985	57.947051911246284
1986	59.753764245903
1987	61.96606525065127
1988	61.79005737187405
1989	63.38992743066429
1990	63.480117283033145
1991	62.80489430330819
1992	62.274325288784325
1993	62.1987951807229
1994	62.66799402687905
1995	63.335558435099024
1996	64.13601228362577
1997	65.41288142723795
1998	62.70603754980212
1999	63.987907289217326
2000	66.25080489375404
2001	67.13378703069841
2002	67.05359873416039
2003	66.02747032937725
2004	67.35075865181665
2005	67.80120080053369
2006	68.42726151536274
2007	68.39159149484536
2008	68.62585697639759
2009	68.02544640419374
2010	68.38767868368546
2011	68.51179920883918
2012	68.69358023010417
2013	69.0918493719294
2014	69.91709063501037
2015	70.57651935188673
2016	71.02735660713321
2017	71.66893613579064
2018	72.16472500677324
2019	73.15320455348167
2020	73.10414977113716
2021	73.8218959639283
2022	74.71798004479739
2023	76.40550483717128