Year % of total labor force 1991 37.76937661826133 1992 37.74608877207279 1993 37.898861972857176 1994 38.00797013720742 1995 38.112212928373566 1996 38.26475336966134 1997 38.50632565815372 1998 38.568978961055144 1999 38.87697684322899 2000 39.141135266462626 2001 39.08866774612289 2002 39.35106378772575 2003 39.54248947994511 2004 39.50648340082424 2005 39.63596054351072 2006 39.57827786684696 2007 39.41267019153469 2008 39.43712636733655 2009 39.465583413104454 2010 39.586140839392456 2011 39.54607668460722 2012 39.688249512335965 2013 39.53836325765397 2014 39.558063464142066 2015 39.753814382326446 2016 39.5160112912687 2017 39.43203275135901 2018 39.35734415546783 2019 39.5107216033939 2020 39.57218548745491 2021 39.873505794101796 2022 39.951425689993165 2023 40.192596842480114