Year	% (national estimate)
1960	86.37
1965	82.07
1970	73.13
1975	74.13
1980	78.88
1985	78.51
1988	73.56
1989	70.91
1990	71.84
1991	71.031
1992	68.812
1993	65.683
1994	67.225
1995	63.683
1996	63.596
1997	62.472
1998	60.879
1999	60.665
2000	57.577
2001	56.33
2002	53.269
2003	50.579
2004	51.311
2005	51.713
2006	51.152
2007	51.638
2008	51.727
2009	52.241
2010	50.922
2011	52.313
2012	50.794
2013	51.898
2014	53.989
2015	54.196
2016	54.276
2017	55.207
2018	56.293
2019	55.937
2020	50.126
2021	53.151
2022	56.107
2023	57.385