Year	% (national estimate)
1960	10.5
1970	25.18
1979	21.53
1981	26.08
1991	45.8
1992	54.8
1993	24.84
1994	43.5
1996	40.45
1997	39.34
1998	36.35
2000	31.091
2001	29.603
2002	31.195
2003	28.452
2004	29.253
2005	28.547
2006	28.217
2007	28.959
2008	29.748
2009	25.483
2010	27.714
2011	29.066
2012	30.734
2013	29.445
2014	29.154
2015	31.781
2016	32.433
2017	32.253
2018	32.976
2019	34.059
2020	28.091
2021	35.646
2022	35.641
2023	38.524