Year	% (national estimate)
1980	23.72
1981	24.2
1982	22.37
1983	24.19
1990	29.423
1992	31.694
1994	32.472
1996	32.98
1997	33.717
1998	34.124
1999	33.19
2000	33.09
2001	32.365
2002	32.168
2003	33.312
2004	34.264
2005	35.322
2006	36.512
2007	37.652
2008	38.995
2009	38.876
2010	42.236
2011	44.615
2012	45.219
2013	46.129
2014	46.733
2015	46.788
2016	47.08
2017	47.806
2018	48.036
2019	48.408
2020	40.455
2021	42.205
2022	45.69
2023	47.169