Year	Percent of total labor force (Units)
1980	0.607
1981	0.232
1982	0.154
1983	0.173
1984	0.117
1985	0.041
1986	0.212
1987	0.315
1988	0.463
1989	0.531
1990	2.082
1991	8.415
1992	9.303
1993	11.290
1994	10.118
1995	10.170
1996	9.890
1997	8.730
1998	7.800
1999	7.000
2000	6.433
2001	5.740
2002	5.843
2003	5.901
2004	6.122
2005	6.800
2006	7.075
2007	7.000
2008	7.425
2009	9.675
2010	10.775
2011	10.675
2012	10.675
2013	9.825
2014	7.525
2015	6.625
2016	4.975
2017	4.000
2018	3.600
2019	3.300
2020	4.125
2021	4.050
2022	3.600
2023	4.125
2024	4.400
2025	4.231
2026	4.096
2027	3.965
2028	3.818
2029	3.689