Year % of total labor force 1991 35.500136233231295 1992 35.6019210179669 1993 35.90721995243612 1994 36.1190907007028 1995 36.14094135519527 1996 36.12445217644783 1997 36.08884843371889 1998 36.06920158565922 1999 36.0535333317735 2000 36.02118387121818 2001 35.989854104343955 2002 36.2218309475268 2003 36.44305451754025 2004 36.65290133447999 2005 36.859677773768865 2006 37.063565725396664 2007 36.52094091112658 2008 37.31957656340145 2009 37.82795532928904 2010 38.50055557490563 2011 38.78344991168236 2012 38.55842866563956 2013 38.717692044731706 2014 39.54807664848502 2015 39.356680879743514 2016 38.76200796626054 2017 39.31580408193476 2018 38.851277456616984 2019 40.19588811960644 2020 39.3405598671553 2021 40.61405436564408 2022 41.04091511821146 2023 41.44996814188261