Year	% (national estimate)
1977	27.47
1978	27.35
1979	27.77
1980	28.3
1982	28
1983	30.316
1984	29.992
1985	30.212
1986	30.622
1987	30.957
1988	31.285
1989	31.811
1990	32.336
1991	33.17
1992	32.244
1993	31.41
1994	31.174
1995	30.879
1996	31.325
1997	31.616
1998	32.157
1999	33.02
2000	34.009
2001	35.369
2002	36.205
2003	37.044
2004	39.201
2005	39.037
2006	39.854
2007	40.139
2008	40.703
2009	40.005
2010	39.866
2011	40.227
2012	40.626
2013	40.112
2014	40.334
2015	40.651
2016	41.415
2017	42.175
2018	42.694
2019	43.24
2020	42.204
2021	42.324
2022	43.716
2023	37.868