Year	% of total labor force (national estimate)
1970	7.5
1971	7.6
1972	7.7
1973	8.9
1974	8.1
1980	7.3
1981	6.6
1982	11.7
1984	9.94
1986	10.7
1987	9.1
1990	8.53
1991	8.95
1992	8.96
1993	8.35
1994	9.04
1995	10.02
1996	11.93
1997	11.44
1998	9.362
1999	10.466
2000	12.627
2001	15.052
2002	16.648
2003	16.661
2004	12.98
2005	12.009
2006	10.844
2007	9.403
2008	8.026
2009	7.74
2010	7.158
2011	6.307
2012	6.451
2013	6.444
2014	6.547
2015	7.488
2016	7.841
2017	7.89
2018	8.336
2019	8.734
2020	10.33
2021	9.301
2022	7.877
2023	9.458