Year % of total labor force 1991 32.338920866552954 1992 32.44948811376645 1993 32.575273871487205 1994 32.739046233188176 1995 32.95639356640993 1996 33.08556656711198 1997 33.2712292893399 1998 33.489239224127154 1999 33.70849750986935 2000 33.916211719792486 2001 34.06704817556967 2002 34.21648122066136 2003 34.36512629374639 2004 34.505982765018764 2005 34.63132272085092 2006 34.707173285208725 2007 35.15017965192017 2008 35.60931699007241 2009 36.08378233095396 2010 36.57618668583099 2011 37.083570321733724 2012 37.607506329404586 2013 38.15204825157759 2014 38.70099301375039 2015 39.248994284947976 2016 40.489914911887425 2017 40.35934748412892 2018 39.18964466830068 2019 38.58930127378611 2020 38.5506584589806 2021 38.92035300056689 2022 38.65776766012493 2023 38.73175595530204