Year	% of total labor force (national estimate)
1990	15.9
1991	14.661
1992	14.22
1993	13.82
1994	13.03
1995	12.27
1996	11.35
1997	10.6
1998	9.17
1999	8.88
2000	7.74
2001	7.9
2002	8.76
2003	8.22
2004	8.38
2005	7.67
2006	6.5
2007	5.97
2008	5.22
2009	5.85
2010	4.784
2011	4.118
2012	3.88
2013	4.186
2014	4.157
2015	4.519
2016	4.243
2017	4.046
2018	4.318
2019	4.67
2020	5.365
2021	4.981
2022	4.528