Year % of total labor force 1991 17.770439403162786 1992 18.097556819928766 1993 17.97628032875708 1994 18.302529915975967 1995 18.22720356966263 1996 18.200470584673283 1997 18.249588573692247 1998 18.36103434780824 1999 18.856378052068326 2000 19.3039528214274 2001 19.654610206645536 2002 19.450099795504453 2003 19.811815619361063 2004 20.15208510179446 2005 20.516719809547318 2006 20.587801248881323 2007 20.91150531822328 2008 20.186260674991715 2009 20.54255916758341 2010 20.321641907050527 2011 20.055855601752555 2012 20.318583557156824 2013 20.15935834604669 2014 20.15736098030636 2015 20.72408975018273 2016 21.291231890990602 2017 21.113455903242897 2018 20.092277146587932 2019 19.27319770638328 2020 18.2622986709076 2021 18.31927336807269 2022 18.15168120604831 2023 18.48905428185945