Year % of total labor force 1991 50.38991298788795 1992 50.310484543318424 1993 50.24893282419818 1994 50.18813585888135 1995 50.18233893022563 1996 50.15487267002641 1997 50.16693975166425 1998 50.21266867674194 1999 50.285870088104055 2000 50.321159868071 2001 50.267734605087824 2002 50.22575450038529 2003 50.19236409541459 2004 50.15786913318805 2005 50.12465518248238 2006 49.8749972009997 2007 49.611929004184525 2008 49.337826241354094 2009 49.05463336219442 2010 48.75897478968762 2011 48.44762262214103 2012 48.12386092022559 2013 48.086140231421815 2014 48.07037814192761 2015 48.07656159638909 2016 48.06540202847125 2017 48.08284382788189 2018 48.12675347405374 2019 48.19474064794632 2020 48.19789531439281 2021 48.308305571012184 2022 48.410862847300315 2023 48.429156358689184