Year	% (national estimate)
1960	64.26886792452831
1961	63.95759717314486
1962	63.345195729537366
1963	62.57521058965103
1964	62.24116930572473
1965	61.933904528763776
1966	62.30110159118727
1967	62.7450980392157
1968	61.75395858708892
1969	61.17216117216117
1970	61.002444987775064
1971	59.36739659367396
1972	58.09987819732035
1973	58.70889159561511
1974	56.84596577017115
1975	56.14250614250614
1976	56.4039408866995
1977	57.81637717121588
1978	59.02864259028643
1979	59.35162094763092
1980	59.64912280701755
1981	59.77443609022557
1982	60.37735849056604
1983	61.712846347607055
1984	62.055837563451774
1985	62.355953905249685
1986	62.46786632390746
1987	62.8719275549806
1988	63.424124513618686
1989	64.28571428571429
1990	64.75521041954698
1991	65.29660361799722
1992	65.04635269076408
1993	64.48384988917219
1994	64.48988509883556
1995	64.38527335497501
1996	64.37945498057178
1997	64.81212292730618
1998	64.84640755351485
1999	64.48362392895685
2000	64.44563596892738
2001	64.91223435869667
2002	64.91601134114374
2003	65.06277561258479
2004	65.69226789385544
2005	65.96159615961597
2006	66.20601127968428
2007	66.21612387421246
2008	66.58644920859749
2009	67.31204285853076
2010	67.61661288294707
2011	67.65019951666386
2012	67.96506204596207
2013	69.23611702278596
2014	69.90954402805981
2015	70.37448067839053
2016	71.35393744942434
2017	72.4495006808897
2018	73.6705978268509
2019	74.65317676074102
2020	74.40648766754906
2021	75.08799483950582
2022	75.91036414565826
2023	76.75070028011204