Year	% (national estimate)
1961	78.66
1966	76.3
1971	70.48
1975	77.6
1977	67.23
1981	67.59
1983	65.413
1984	63.356
1985	62.279
1986	60.53
1987	58.212
1988	56.541
1989	54.564
1990	53.929
1991	53.23
1992	49.568
1993	49.395
1994	49.292
1995	48.321
1996	46.689
1997	49.119
1998	52.25
1999	54.272
2000	55.961
2001	54.737
2002	52.784
2003	53.197
2004	52.912
2005	53.356
2006	57.186
2007	74.469
2008	70.049
2009	62.731
2010	56.015
2011	53.569
2012	51.918
2013	51.621
2014	50.208
2015	50.139
2016	52.553
2017	47.84
2018	48.361
2019	48.189
2020	44.247
2021	52.528
2022	50.879
2023	53.602