Year	% of total labor force (national estimate)
1992	1.8
1993	5.3
1994	6.6
1995	6.7
1996	9.3
1997	10.8
1998	9.4
1999	11.2
2007	10.394
2008	22.974
2009	19.295
2010	19.523
2011	18.884
2012	17.511
2013	16.576
2014	17.499
2015	18.261
2016	17.617
2017	17.705
2018	13.212
2019	12.2
2020	12.18
2021	10.012
2022	8.766