Year	% (national estimate)
1960	82.06092036115102
1970	70.06582718408676
1980	70.38790955948943
1990	69.46672480698997
1991	71.32456968698905
1992	72.8028447028135
1993	72.72296047190358
1995	71.14041761681725
1996	70.19756221238025
1997	70.88767304749246
1998	70.71387065489613
1999	70.52397375801553
2001	68.68025037264202
2002	68.98516987995524
2003	68.03839279956264
2004	67.17772926858471
2005	65.77106991846861
2006	66.91612919065395
2007	65.33588992454615
2008	64.56257139520463
2009	64.08190749410014
2011	62.19841942031334
2012	61.67069183362587
2013	60.60631944168973
2014	60.14508567011983
2015	60.37704084287785
2016	58.86052835583076
2017	58.62419492433107
2018	58.855849319487405
2019	58.950063206738356
2020	53.25801867813747
2021	57.54203644655234
2022	57.81318767905311
2023	55.870014879583906