Year % of total labor force 1991 0.7247164546871037 1992 0.7036440317114271 1993 0.683966591944945 1994 0.6668282296205861 1995 1.171303074670571 1996 1.293337037256304 1997 1.533996757202204 1998 1.5712937893390857 1999 1.537801466755039 2000 1.5058343552092583 2001 1.4121577918843948 2002 1.4669646808102481 2003 1.6316914398615565 2004 2.042384944348908 2005 2.0131989008241358 2006 1.9834333352158284 2007 1.9574568421857947 2008 1.93330995651676 2009 2.3001023106876834 2010 2.272311841393201 2011 2.2489633027640648 2012 2.2293886133146295 2013 2.210919320575733 2014 2.1900198677491773 2015 2.175193902215571 2016 2.12712224367674 2017 1.4652461279889875 2018 1.425049120140707 2019 1.3964582328070432 2020 1.371322391894799