Year	% (national estimate)
1977	24.64
1979	25.43
1980	25.61
1983	29.835
1984	29.478
1985	29.957
1986	30.317
1987	30.123
1988	30.918
1989	31.506
1990	32.375
1991	33.962
1992	35.206
1993	35.295
1994	35.172
1995	35.583
1996	35.519
1997	36.274
1998	36.784
1999	38.762
2000	40.035
2001	38.969
2002	39.253
2003	39.515
2004	40.584
2005	41.349
2006	41.556
2007	42.597
2008	43.346
2009	43.145
2010	43.648
2011	43.655
2012	43.61
2013	43.866
2014	44.26
2015	44.279
2016	44.164
2017	45.283
2018	46.766
2019	47.371
2020	46.688
2021	47.11
2022	48.133
2023	48.125