Year	Percent of total labor force
1980	1.2
1981	0.9
1982	4.2
1983	6.1
1984	5.6
1985	4.4
1986	4.3
1987	3.883
1988	3.542
1989	2.925
1990	2.742
1991	2.692
1992	2.83
1993	3.43
1994	3.7
1995	6.23
1996	5.45
1997	3.73
1998	3.16
1999	2.5
2000	2.2
2001	2.768
2002	2.978
2003	3.4
2004	3.919
2005	3.478
2006	3.528
2007	3.61
2008	3.887
2009	5.329
2010	5.272
2011	5.171
2012	4.891
2013	4.904
2014	4.823
2015	4.35
2016	3.883
2017	3.421
2018	3.329
2019	3.485
2020	3.564
2021	3.563
2022	3.514
2023	3.47
2024	3.442