Year % of total labor force 1991 35.23268351657213 1992 35.64694413461964 1993 36.11852337723721 1994 36.61486005137393 1995 37.1848003785859 1996 37.33781780750923 1997 37.79789278364912 1998 38.084711571715964 1999 38.32318874523512 2000 38.54863639516633 2001 38.939021116611734 2002 39.275182108843765 2003 39.57840783251414 2004 39.984182738898355 2005 40.253979115493806 2006 40.41920612927763 2007 40.53738541247341 2008 40.544125994945645 2009 40.885283425381736 2010 40.784373762475 2011 40.6356017835319 2012 40.802666433551934 2013 40.82727450700228 2014 40.75903862335211 2015 40.944770853962275 2016 41.144954230620414 2017 41.32753523914702 2018 41.553989550531796 2019 41.83163883597137 2020 41.20000679141422 2021 41.60004560146372 2022 41.90415204857849 2023 42.0143382258229