Year % of total labor force 1991 27.507062400713068 1992 27.936546122223717 1993 28.434086044744383 1994 28.687452680845205 1995 28.8714481970647 1996 29.283232582893177 1997 29.81592903988534 1998 29.93867918360943 1999 30.25244352385268 2000 30.20678750332117 2001 29.484955169444305 2002 30.830180642898302 2003 30.554054305894628 2004 28.996120730438076 2005 30.948880762958936 2006 31.174017377924052 2007 32.67185504374709 2008 33.678441644249375 2009 34.04557657925235 2010 34.306170223672744 2011 34.96001822657635 2012 36.97830117604313 2013 37.73089621561675 2014 38.25126244198604 2015 38.35329481940726 2016 38.851932535315655 2017 39.16223916223916 2018 39.77937389457378 2019 40.09534137634992 2020 40.66131348740044 2021 40.66078733915604 2022 41.619681518722814 2023 41.709934675146876