Year	% (national estimate)
1980	39.952
1981	38.162
1982	37.522
1983	33.618
1984	30.817
1985	28.551
1986	27.821
1987	27.661
1988	25.518
1989	25.78
1990	25.665
1991	28.295
1992	28.734
1993	27.1
1994	28.856
1995	28.766
1996	28.101
1997	26.482
1998	22.058
1999	23.019
2000	22.952
2001	23.393
2002	24.598
2003	23.892
2004	24.319
2005	22.304
2006	20.565
2007	19.406
2008	16.889
2009	16.487
2010	16.385
2011	17.513
2012	18.398
2013	18.989
2014	20.758
2015	21.786
2016	21.811
2017	21.816
2018	20.287
2019	21.693
2020	20.372
2021	21.195
2022	22.926
2023	21.556