Year Percent of total labor force 1980 0.723 1981 1.015 1982 1.33 1983 1.615 1984 1.748 1985 1.667 1986 1.458 1987 1.669 1988 1.536 1989 1.402 1990 1.256 1991 1.38 1992 1.634 1993 2.105 1994 2.732 1995 2.961 1996 3.241 1997 3.302 1998 3.057 1999 2.89 2000 2 2001 2 2002 2.417 2003 3 2004 4 2005 4 2006 4 2007 4 2008 4.083 2009 5.583 2010 6 2011 6 2012 6.095 2013 6.821 2014 7.074 2015 6.773 2016 6.342 2017 5.821 2018 4.957 2019 5.001 2020 4.974 2021 5.041 2022 5.062 2023 5.036 2024 5.011