Year % of total labor force 1991 0.38225593631236904 1992 0.36526437246629917 1993 0.3631131424240479 1994 0.3480774405677564 1995 0.3744340648707985 1996 0.36597640805171755 1997 0.3631544972460393 1998 0.37335807136066435 1999 0.37450329220901796 2000 0.36671868262263047 2001 0.372785267715496 2002 0.37584372331515153 2003 0.3771871016793489 2004 0.37699987166984444 2005 0.4080006099609119 2006 0.3773456750525454 2007 0.36177598702318503 2008 0.3626720592305217 2009 0.39181094037951203 2010 0.3931382427595356 2011 0.3951889499161071 2012 0.3965267492473051 2013 0.3950214825241386 2014 0.39379222779343404 2015 0.39326963374426627 2016 0.39131889135783726 2017 0.3882479343573598 2018 0.38187183410300163 2019 0.3780114313263808 2020 0.37881877629053107