Year Percent of total labor force 1980 21.5 1981 21.861 1982 22.229 1983 22.603 1984 22.982 1985 23.369 1986 23.762 1987 24.161 1988 24.567 1989 24.98 1990 25.4 1991 25.827 1992 26 1993 26 1994 26 1995 26 1996 25 1997 25 1998 24 1999 22 2000 20 2001 21 2002 20.5 2003 20 2004 19.5 2005 21.4 2006 13.4 2007 15.2 2008 13 2009 13 2010 10.7 2011 12.2 2012 16.8 2013 16.4 2014 12 2015 10 2016 9 2017 9 2018 8.5 2019 8.5 2020 8.5 2021 8.5 2022 8.5 2023 8.5 2024 8.5