Year Percent of total labor force (Units) 1980 0.209 1981 0.190 1982 0.428 1983 0.850 1984 1.138 1985 0.982 1986 0.832 1987 0.798 1988 0.720 1989 0.564 1990 0.501 1991 1.083 1992 2.549 1993 4.504 1994 4.723 1995 4.233 1996 4.656 1997 5.199 1998 3.856 1999 2.723 2000 1.824 2001 1.703 2002 2.546 2003 3.691 2004 3.879 2005 3.763 2006 3.332 2007 2.766 2008 2.577 2009 3.701 2010 3.516 2011 2.843 2012 2.905 2013 3.158 2014 3.044 2015 3.178 2016 3.323 2017 3.088 2018 2.547 2019 2.306 2020 3.170 2021 2.993 2022 2.166 2023 2.035 2024 2.250 2025 2.400 2026 2.500 2027 2.500 2028 2.500 2029 2.500