Year	% (national estimate)
1961	43.993546785802934
1971	35.56715188135128
1981	43.888156931635194
1982	43.153284671532845
1983	46.52895079334312
1984	47.598828491753196
1985	49.50589644502117
1986	50.12824414206843
1987	50.759260906960876
1988	52.396303779415256
1989	53.546883224302576
1990	53.78735868918486
1991	51.12783121315545
1992	53.91338093759702
1993	54.62896646218043
1994	54.701462539810144
1995	56.211131597862426
1996	57.745055355143684
1997	58.146406557793725
1998	61.17916129428379
1999	61.838310540515394
2000	62.05430160287864
2001	61.42852645827431
2002	62.168214865866545
2003	62.947643237972414
2004	64.85738109847233
2005	65.16080354616618
2006	65.56254017024345
2007	65.56818003237314
2008	65.55942410840312
2009	67.47792138280622
2010	68.87421413527166
2011	70.06765286634513
2012	71.44309776458432
2013	71.44057603269017
2014	73.09703175372076
2015	74.55346631235494
2016	74.78334034497266
2017	74.23932025792584
2018	73.37355455002513
2019	73.42687786745252
2020	74.43936948384216
2021	74.35222983244232
2022	74.00891274456207
2023	74.78707268696768