Year	% (national estimate)
1960	60.44
1970	52.03
1978	52.44
1988	44.34
1992	44.782
1993	42.218
1994	41.521
1995	39.681
1996	38.961
1997	36.012
1998	35.319
1999	34.498
2000	37.517
2001	39.787
2002	37.731
2003	36.168
2004	35.143
2005	35.692
2006	34.168
2007	32.978
2008	33.069
2009	33.767
2010	34.58
2011	33.53
2012	33.581
2013	33.296
2014	33.861
2015	32.831
2016	34.509
2017	34.804
2018	35.086
2019	35.188
2020	31.843
2021	31.034
2022	31.142
2023	32.364