Year % of total labor force 1991 17.752746271782176 1992 18.077860654373918 1993 17.957006638465202 1994 18.28051823202315 1995 18.205460288131505 1996 18.17762557770034 1997 18.22748598274811 1998 18.340128926492838 1999 18.8333527963171 2000 19.275804605712143 2001 19.61453631691073 2002 19.41386485672549 2003 19.786009072705717 2004 20.12948822703151 2005 20.489041304097384 2006 20.566553086971926 2007 20.897551184697377 2008 20.17679130138161 2009 20.52805197018103 2010 20.301047450548214 2011 20.048254385690388 2012 20.313022849779298 2013 20.15078649583335 2014 20.155586675283832 2015 20.72463434471519 2016 21.280384294203277 2017 21.10574951088255 2018 20.097653072193395 2019 19.29208087383915 2020 18.28385340164206 2021 18.343235067948324 2022 18.187328616673774 2023 18.48905428185945