Year % of total labor force 1991 35.40549663623447 1992 35.23015161554351 1993 34.45508065649546 1994 34.52005442681757 1995 34.303060583350366 1996 34.534558943059395 1997 34.76627020477053 1998 34.99961276604733 1999 35.239280337144315 2000 35.422804901359804 2001 35.61337772320468 2002 35.812016294519175 2003 36.0169267700037 2004 36.30777999430037 2005 36.66798478409793 2006 37.02238570449129 2007 37.37826401292847 2008 37.73393847496001 2009 38.09340297145175 2010 38.46039633361708 2011 38.8328415440413 2012 39.19549924374856 2013 39.54109422185043 2014 39.873295701648594 2015 40.195658258405345 2016 40.5215544266868 2017 40.659562139420046 2018 41.07175984136734 2019 41.15551588428612 2020 41.08403407716176 2021 41.44740359897172 2022 41.559122521065106 2023 41.72481317188187