Year	Percent of total labor force
1980	4.78
1981	5.115
1982	5.048
1983	4.562
1984	5.893
1985	6.693
1986	7.078
1987	6.057
1988	6.428
1989	8.881
1990	9.567
1991	10.585
1992	11.155
1993	10.015
1994	7.828
1995	6.863
1996	8.325
1997	9.525
1998	10.675
1999	11.075
2000	10.9
2001	11.625
2002	12.875
2003	13.4
2004	12.9
2005	11.2
2006	10.45
2007	9.15
2008	7.65
2009	9.425
2010	8.25
2011	7.05
2012	6.875
2013	6.25
2014	5.9
2015	5.275
2016	4.775
2017	4.25
2018	3.984
2019	3.974
2020	3.974
2021	4.106
2022	4.144
2023	4.153
2024	4.162