Year % of total labor force 1991 36.89154780377862 1992 36.291899671844504 1993 36.158751726573 1994 36.53681237899359 1995 36.895429700490894 1996 37.2648373625183 1997 37.47374276765363 1998 37.813251032563 1999 38.37437862479543 2000 38.63748406890423 2001 39.0955886892798 2002 39.31467150773047 2003 39.51555459817207 2004 40.27731036531838 2005 40.34228219735897 2006 40.5143948440316 2007 40.527816316636674 2008 41.023400285525895 2009 41.09217100998844 2010 41.2759170523959 2011 41.58561196644654 2012 42.1605737347749 2013 42.34797967624914 2014 42.56540079132374 2015 42.23316017783774 2016 42.426961250530994 2017 42.59246851339169 2018 42.603921913958345 2019 42.751110395743616 2020 42.439759524040454 2021 42.640099757450486 2022 42.766390610921604 2023 42.7821781927498