Year % of total labor force 1991 23.93153667132822 1992 24.53969575448359 1993 23.441575398297527 1994 23.78594338449552 1995 22.80973334582551 1996 22.35024601101716 1997 21.891433992845975 1998 21.436692832179613 1999 21.58876849239606 2000 22.059677380765034 2001 22.598735063448107 2002 21.007406126652587 2003 21.362392422230624 2004 21.72807227044114 2005 22.106426997591296 2006 22.49916045591051 2007 24.17972944906248 2008 22.862823264302996 2009 23.75250002162617 2010 23.31573759277604 2011 22.904037699917442 2012 23.006111639341825 2013 23.553181519957818 2014 23.86637943407699 2015 24.075383741242053 2016 24.51928223859426 2017 24.470342847328798 2018 21.095697438048205 2019 18.648238488879638 2020 17.424072843125312 2021 18.008255241520605 2022 18.411393847513423 2023 18.598189519818632