Year % of total labor force 1991 35.12267702982736 1992 35.166651447857205 1993 35.24483649762787 1994 35.33308062810581 1995 35.44872129291043 1996 35.588230370343595 1997 35.68658965839953 1998 35.44970170264949 1999 35.52140008423014 2000 35.58594433873952 2001 35.39071221788221 2002 35.31180003324866 2003 35.24982648181199 2004 35.21921277688242 2005 35.1575368691365 2006 35.10653295841261 2007 35.07743060092424 2008 34.78144291936117 2009 35.007914207868694 2010 34.91694826283786 2011 35.5850430668308 2012 36.10553408082354 2013 37.3533830190578 2014 37.94877326585021 2015 38.13867745913857 2016 38.36047609313892 2017 38.5893232065122 2018 38.69610688097316 2019 38.745438103592065 2020 38.73915268169596 2021 39.01517215279872 2022 38.89384464083492 2023 38.94691240093464