Year	% (national estimate)
1960	12.069721552291163
1970	32.71393643031785
1979	34.45516891033782
1981	39.70110461338531
1991	52.24719101123596
1992	58.04676753782668
1993	30.368319691863267
1994	54.172767203513914
1996	51.99757869249395
1997	49.77256404117787
1998	47.895953757225435
2000	51.20186458693509
2001	50.1475770065922
2002	53.10582822085889
2003	52.66941140182655
2004	52.31758054192447
2005	53.93616444299817
2006	54.621093173369836
2007	54.078242229367625
2008	56.83326561018557
2009	53.84371248395867
2010	57.8344814203939
2011	59.840440089769565
2012	61.109161582896945
2013	61.11096072114993
2014	61.28266673858518
2015	63.200774169925076
2016	63.88262733396745
2017	64.4298377698925
2018	64.79397384731863
2019	67.21843763926911
2020	64.3568229644418
2021	67.50966621952182
2022	66.12026830282862
2023	68.66397814492