Year	% of total labor force (national estimate)
1960	1.7
1961	1.4
1962	1.3
1963	1.3
1964	1.1
1965	1.2
1966	1.3
1967	1.3
1968	1.2
1969	1.1
1970	1.1
1971	1.2
1972	1.4
1973	1.3
1974	1.4
1975	1.9
1976	2
1977	2
1978	2.2
1979	2.1
1980	2
1981	2.2
1982	2.4
1983	2.6
1984	2.7
1985	2.6
1986	2.8
1987	2.8
1988	2.5
1989	2.3
1990	2.095
1991	2.059
1992	2.158
1993	2.539
1994	2.89
1995	3.15
1996	3.383
1997	3.374
1998	4.078
1999	4.677
2000	4.748
2001	5.02
2002	5.386
2003	5.251
2004	4.734
2005	4.446
2006	4.192
2007	3.888
2008	4.002
2009	5.068
2010	5.103
2011	4.55
2012	4.358
2013	4.038
2014	3.589
2015	3.385
2016	3.132
2017	2.822
2018	2.467
2019	2.351
2020	2.809
2021	2.828
2022	2.6
2023	2.6