Year	% (national estimate)
1964	14.85
1973	16.08
1978	14.31
1979	16.26
1980	16.28
1981	15.07
1985	14.86
1987	26.47
1989	27.52
1994	18.32
1999	27.48
2003	45.165
2004	34.614
2006	41.42
2010	33.378
2011	35.468
2012	39.751
2013	32.495
2014	32.915
2015	31.466
2016	33.812
2017	31.179
2018	33.262
2019	32.327
2021	36.49
2022	34.284