Year	% of total labor force (national estimate)
1960	5.5
1961	6.7
1962	5.5
1963	5.7
1964	5.2
1965	4.5
1966	3.8
1967	3.8
1968	3.6
1969	3.5
1970	4.9
1971	5.9
1972	5.6
1973	4.9
1974	5.6
1975	8.5
1976	7.7
1977	7.1
1978	6.1
1979	5.8
1980	7.1
1981	7.6
1982	9.7
1983	9.6
1984	7.5
1985	7.2
1986	7
1987	6.2
1988	5.5
1989	5.3
1990	5.6
1991	6.8
1992	7.5
1993	6.9
1994	6.119
1995	5.65
1996	5.451
1997	5
1998	4.511
1999	4.219
2000	3.992
2001	4.731
2002	5.783
2003	5.989
2004	5.529
2005	5.084
2006	4.623
2007	4.622
2008	5.784
2009	9.254
2010	9.633
2011	8.949
2012	8.069
2013	7.375
2014	6.168
2015	5.28
2016	4.869
2017	4.355
2018	3.896
2019	3.669
2020	8.055
2021	5.349
2022	3.65
2023	3.638