Year	Percent of total labor force
1980	5.2
1981	4.5
1982	4.133
1983	4.117
1984	3.85
1985	4.025
1986	3.842
1987	3.108
1988	2.525
1989	2.583
1990	2.458
1991	2.45
1992	2.525
1993	2.9
1994	2.475
1995	2.067
1996	2.058
1997	2.617
1998	6.95
1999	6.55
2000	4.425
2001	4
2002	3.258
2003	3.55
2004	3.658
2005	3.75
2006	3.475
2007	3.258
2008	3.175
2009	3.633
2010	3.708
2011	3.408
2012	3.225
2013	3.1
2014	3.492
2015	3.592
2016	3.675
2017	3.683
2018	3.842
2019	4
2020	3.85
2021	3.9
2022	3.8
2023	3.7
2024	3.6