Year	% (national estimate)
1991	58.7
1993	59.535
1994	60.078
1995	58.786
1996	57.749
1997	56.138
1998	55.75
1999	54.185
2000	51.328
2001	48.065
2002	44.694
2003	42.091
2004	39.975
2005	38.743
2006	37.704
2007	36.721
2008	35.888
2009	37.253
2010	36.19
2011	35.458
2012	36.387
2013	36.785
2014	38.061
2015	37.36
2016	37.476
2017	36.475
2018	34.369
2019	33.368
2020	32.866
2021	31.855
2022	31.847
2023	31.715