Year	% (national estimate)
1960	50.57
1970	42.07
1978	46.32
1979	46.92
1980	49.35
1990	41.11
1991	52.176
1992	53.336
1993	54.535
1994	54.126
1995	54.357
1996	53.072
1997	53.114
1998	53.771
1999	52.425
2000	51.521
2001	49.561
2002	47.24
2003	47.149
2004	46.958
2005	47.887
2006	48.381
2007	48.354
2008	47.723
2009	46.922
2010	47.066
2011	46.86
2012	47.228
2013	46.349
2014	45.563
2015	44.827
2016	44.233
2017	43.808
2018	43.786
2019	44.879
2020	39.995
2021	44.475
2022	44.249
2023	44.721