Year % of total labor force 1991 38.06428596943022 1992 38.05575957756902 1993 38.170018393711466 1994 38.28050783915485 1995 38.232693997299364 1996 38.27831897701198 1997 38.33215322896727 1998 38.455746743535435 1999 38.49078329013912 2000 38.539324526324094 2001 38.52445689055324 2002 38.53046604586174 2003 38.60612577066282 2004 38.6808019864653 2005 38.78002845354075 2006 38.82487452866448 2007 38.874721126366104 2008 38.95409855637671 2009 39.06058180036014 2010 39.15853298041171 2011 39.254195992791765 2012 39.313048856448916 2013 39.4653269663974 2014 39.611186203581696 2015 39.78592767416309 2016 39.811021056934536 2017 39.9053587351599 2018 39.86497279270031 2019 39.966732309817914 2020 39.9542790836559 2021 40.15099898295712 2022 39.91563889544111 2023 39.98964209458193