Year	% of total labor force (national estimate)
1983	8.5
1985	8.1
1986	6.8
1987	4.4
1988	4
1989	3.7
1990	3.9
1991	3.6
1992	4
1993	4.5
1994	4.1
1995	3.7
1996	4.4
1997	5
1998	5.1
1999	5.3
2000	6.324
2001	7.107
2002	6.902
2003	7.488
2004	7.317
2005	6.923
2006	6.798
2007	6.472
2008	5.977
2009	6.889
2010	6.847
2011	6.378
2012	6.197
2013	6.106
2014	5.725
2015	5.379
2016	4.687
2017	4.002
2018	3.658
2019	3.616
2020	4.347
2021	3.394
2022	2.921
2023	3.11