Year % of total labor force 1991 0.38186740799859475 1992 0.34616659440439007 1993 0.33948873562229837 1994 0.33253100990221923 1995 0.4123488721037578 1996 0.403252122246942 1997 0.3925963837078979 1998 0.38218459743096267 1999 0.3721391193131879 2000 0.36070130775581377 2001 0.3491308135735629 2002 0.337750307419441 2003 0.26228876617214486 2004 0.22892091053084052 2005 0.2419687057839998 2006 0.23438351471362046 2007 0.2271066555308703 2008 0.22022943135109105 2009 0.21643016698077244 2010 0.21023172727252276 2011 0.2041476415906714 2012 0.1279595988893107 2013 0.18888918591802306 2014 0.21438851424409716 2015 0.23829115680402696 2016 0.26254310758706806 2017 0.2593536618575774 2018 0.2963386094776425 2019 0.290284990745438 2020 0.5593369156361679