Year Percent of total labor force (Units) 1980 1.230 1981 1.360 1982 2.140 1983 2.710 1984 2.450 1985 2.910 1986 2.660 1987 1.970 1988 1.690 1989 1.570 1990 1.670 1991 1.510 1992 1.510 1993 1.450 1994 1.560 1995 1.790 1996 2.600 1997 2.720 1998 2.690 1999 2.920 2000 2.990 2001 4.570 2002 5.170 2003 4.990 2004 4.440 2005 4.130 2006 3.910 2007 3.910 2008 4.140 2009 5.850 2010 5.210 2011 4.390 2012 4.240 2013 4.180 2014 3.960 2015 3.780 2016 3.920 2017 3.760 2018 3.710 2019 3.730 2020 3.850 2021 3.950 2022 3.670 2023 3.670 2024 3.670 2025 3.670 2026 3.670 2027 3.670 2028 3.670 2029 3.670