Year	Percent of total labor force
1980	9.241
1981	9.824
1982	10.755
1983	12.543
1984	13.718
1985	15.452
1986	16.049
1987	16.592
1988	17.238
1989	17.829
1990	18.784
1991	20.162
1992	21.213
1993	22.163
1994	22.89
1995	16.5
1996	20.3
1997	22
1998	26.1
1999	23.3
2000	23
2001	25.95
2002	27.8
2003	27.65
2004	25.15
2005	24.65
2006	23.55
2007	23
2008	22.525
2009	23.7
2010	24.875
2011	24.8
2012	24.875
2013	24.725
2014	25.1
2015	25.35
2016	26.725
2017	27.45
2018	27.125
2019	27.527
2020	27.836
2021	27.974
2022	28.106
2023	28.231
2024	28.351