Year % of total labor force 1991 0.3633317312134138 1992 0.3518865812576493 1993 0.34078749173590334 1994 0.33000147086369874 1995 0.43381735680412076 1996 0.42008953655722325 1997 0.4069185287710675 1998 0.39423236664329403 1999 0.3820227851793389 2000 0.3702253113302585 2001 0.2718155580430035 2002 0.2632058028105993 2003 0.2550077741953383 2004 0.24012310768698103 2005 0.24358437508096412 2007 0.22790013540375773 2008 0.22041296573259658 2009 0.2092603113018394 2010 0.20234006282658948 2011 0.19566762881995753 2012 0.18927189380725146 2013 0.18318404399130894 2014 0.17742583210045654 2015 0.17199614505677108 2016 0.16698583380317425 2017 0.1651518984586073 2018 0.15675974258154568 2019 0.1558226166328744 2020 0.15273991100817366