Year Percent of total labor force (Units) 1990 16.198 1991 16.223 1992 16.247 1993 16.272 1994 16.296 1995 16.177 1996 16.058 1997 15.939 1998 16.063 1999 15.982 2000 15.691 2001 15.126 2002 15.263 2003 14.514 2004 14.237 2005 12.819 2006 12.511 2007 12.397 2008 12.442 2009 13.290 2010 13.048 2011 18.889 2012 16.723 2013 15.330 2014 14.959 2015 15.390 2016 15.544 2017 15.513 2018 15.530 2019 14.889 2020 17.400 2021 16.200 2022 15.200 2023 16.400