Year % of total labor force 1991 35.88342732227921 1992 36.83791646769888 1993 37.92908525415967 1994 38.108892056326155 1995 38.296652259629965 1996 38.23043530135188 1997 38.583507239517225 1998 38.57558583194661 1999 40.5825553614145 2000 39.93143630417622 2001 40.53534977277807 2002 41.14596220305646 2003 41.53847159659251 2004 41.02628225653153 2005 41.63180740799126 2006 42.44641812476733 2007 42.43507471078817 2008 42.69550751236879 2009 42.71370668458117 2010 42.75268793202822 2011 43.16136685619924 2012 42.940366964806756 2013 42.71895607612113 2014 42.49954402191422 2015 42.282616670766814 2016 42.023717205865694 2017 41.63556396798227 2018 41.254208303902786 2019 40.96734379660739 2020 41.01750762699004 2021 41.131644956084514 2022 41.00612885252632 2023 41.24621367029646