Year % of total labor force 1991 39.43407559088992 1992 39.45881681647619 1993 39.4430065903199 1994 39.545484092086035 1995 39.5610741107105 1996 39.57127865415014 1997 39.58806580346287 1998 39.61610633367052 1999 39.65872868999586 2000 39.66415378939549 2001 39.664860194856175 2002 39.67338854190433 2003 39.71302779655368 2004 39.721850118882315 2005 39.790478856352095 2006 39.73832244751587 2007 39.72869647552174 2008 39.63473323833514 2009 39.61441070629481 2010 39.5023079269117 2011 39.45556116591173 2012 39.426695212929744 2013 39.43332714419567 2014 39.462503030032686 2015 39.519390408288224 2016 39.57732751060471 2017 39.63683365215807 2018 39.65564009570725 2019 39.73595265588071 2020 39.59206542892437 2021 39.823237681243796 2022 39.73349504814771 2023 40.08679441231539