Year Percent of total labor force 1980 2.017 1981 2.208 1982 2.35 1983 2.658 1984 2.708 1985 2.625 1986 2.767 1987 2.85 1988 2.517 1989 2.25 1990 2.1 1991 2.092 1992 2.15 1993 2.5 1994 2.892 1995 3.15 1996 3.367 1997 3.4 1998 4.1 1999 4.667 2000 4.733 2001 5.042 2002 5.358 2003 5.242 2004 4.733 2005 4.425 2006 4.117 2007 3.833 2008 3.983 2009 5.075 2010 5.058 2011 4.583 2012 4.325 2013 4.008 2014 3.583 2015 3.375 2016 3.108 2017 2.817 2018 2.442 2019 2.433 2020 2.433 2021 2.433 2022 2.433 2023 2.433 2024 2.433