Year	% (national estimate)
1960	78.43
1976	50.04
1988	71.49
1989	75.23
1990	73.02
1991	71.13
1992	58.13
1995	60.81
1999	44.25
2000	42.074
2001	42.952
2002	40.919
2003	42.421
2004	45.751
2005	46.873
2006	45.176
2007	43.888
2008	43.144
2009	42.237
2010	40.972
2011	41.397
2012	43.25
2013	41.003
2014	41.248
2015	36.863
2016	35.81
2017	33.327
2018	36.838
2019	37.712
2020	40.352
2021	44.396
2022	43.695
2023	45.14