Year % of total labor force 1991 19.811923825217765 1992 20.076961243813734 1993 19.91473205434374 1994 20.205585619667115 1995 20.15473736151349 1996 20.16519657950361 1997 20.10474127572556 1998 20.10147713606079 1999 20.43075203681589 2000 20.62547169306236 2001 20.75242322731257 2002 20.339380176078006 2003 20.500139795852913 2004 20.642909333714496 2005 20.787425678376458 2006 20.941311250387603 2007 21.337137236941086 2008 20.908591323795253 2009 21.017958099015118 2010 20.90377674654494 2011 20.940073455987626 2012 20.999750190363706 2013 21.189269420366674 2014 21.297902923910296 2015 21.646701185013487 2016 21.85287285341556 2017 21.40382153216838 2018 20.67980944863515 2019 20.29001966837956 2020 20.39128240485599 2021 20.826204603099146 2022 20.701887760378476 2023 20.862644405375566