Year	% (national estimate)
1976	52.97
1978	78.37
1979	75.15
1980	78.14
1982	79.67
1984	79.22
1987	79.16
1988	79.77
1989	81.79
1990	79.49
1994	68.58
1996	64.44
1997	63.04
1998	61.86
1999	57.93
2000	57.81
2001	60.44
2003	57.77
2004	59
2005	57.58
2006	57.02
2007	56.72
2008	57.1
2009	56.54
2010	54.273
2011	55.95
2012	55.77
2013	52.973
2014	50.812
2015	49.53
2016	48.691
2017	47.997
2018	49.112
2019	47.285
2020	47.004
2021	46.113
2022	45.295
2023	46.447