Year	% (national estimate)
1960	11.26
1970	16.83
1980	11.86
1985	13.85
1991	11.64
1997	17.3
1998	20.4
1999	25.7
2000	26.771
2001	29.285
2002	30.022
2003	28.076
2004	26.251
2005	26.77
2006	28.557
2007	26.64
2008	32.09
2009	29.812
2010	25.605
2011	27.629
2012	26.687
2013	27.222
2014	25.688
2015	27.208
2016	27.425
2017	28.263
2018	26.271
2019	27.038
2020	23.64
2021	24.618
2022	26.69
2023	28.735