Year % of total labor force 1991 2.147431342412489 1992 2.0133565143015693 1993 1.9048681568045773 1994 1.7507903833708491 1995 2.5057254099433806 1996 2.4309082004185236 1997 2.37536830076345 1998 2.296086481753316 1999 2.360284948163786 2000 2.353334208209785 2001 2.0048572972391874 2002 1.9781273509368764 2003 1.8843084012178064 2004 1.7705044466518656 2005 1.7191993145634046 2007 1.6192513328374911 2008 1.6053927716382068 2009 1.6859964898733197 2010 1.708073745765716 2011 1.6580767904962614 2012 1.6286575556672076 2013 1.5711167995111455 2014 1.5201380310509287 2015 1.484807402398546 2016 1.4449109459615572 2017 1.370936961936149 2018 1.3213733661142317 2019 1.303912572385996 2020 1.183559587650744