Year % of total labor force 1991 0.3610561252720332 1992 0.35081072358219845 1993 0.34038178923389417 1994 0.33016921172100705 1995 0.4020200704499971 1996 0.3917129214341394 1997 0.38066930800410514 1998 0.3662103956403947 1999 0.35926482919472225 2000 0.37670485105159945 2001 0.2859220168122146 2002 0.2359224101035932 2003 0.23321454507292164 2004 0.12681029623519252 2005 0.1859429601375482 2007 0.17930444220778755 2008 0.1758021265025222 2009 0.18085425214183107 2010 0.17754821138495497 2011 0.17560584014851235 2012 0.4545145282919958 2013 0.45651383629021736 2014 0.46340994665383906 2015 0.46558285832456436 2016 0.4575235680775421 2017 0.4408736131080543 2018 0.548821008111196 2019 0.5281847294400133 2020 0.5176503230655666