Year % of total labor force 1991 0.5041640801999011 1992 0.4666389835682103 1993 0.46086409683111074 1994 0.454126447210162 1995 1.6489535665632948 1996 1.6253477989872311 1997 1.2465644805600091 1998 1.1883897520947122 1999 0.42988524841756576 2000 0.3861531728334771 2001 0.35399932053264743 2002 0.3106477305474721 2003 0.2828442759453131 2004 0.2743018469391704 2005 0.2747401546865568 2006 0.4974942230294616 2007 0.29493232064356895 2008 0.29055629251670395 2009 0.3658568796035299 2010 0.3859397728261243 2011 0.3684590294142693 2012 0.2917491507915117 2013 0.3558770898784081 2014 0.3741834271271293 2015 0.35531160135413725 2016 0.3474164910413707 2017 0.3364690567073172 2018 0.3771316932514713 2019 0.37278418632913407 2020 0.38829634672472907