Year	% of total labor force (national estimate)
1990	1.7
1991	8.5
1992	9.942
1993	12.098
1994	10.847
1995	10.168
1996	10.022
1997	8.991
1998	8.925
1999	6.929
2000	6.563
2001	5.671
2002	5.608
2003	5.79
2004	5.832
2005	7.189
2006	7.494
2007	7.406
2008	7.817
2009	10.03
2010	11.172
2011	11.029
2012	11.003
2013	10.177
2014	7.725
2015	6.813
2016	5.115
2017	4.156
2018	3.709
2019	3.419
2020	4.25
2021	4.045
2022	3.609
2023	4.107