Year % of total labor force 1991 2.78062792139721 1992 2.754714694199122 1995 3.609559143915701 1996 3.5176144543803094 1997 2.5684554531978496 1998 2.528113960330988 1999 2.4904032599957837 2000 2.4356305689678113 2001 2.3160359757588234 2002 2.111204013377926 2003 2.021305763523236 2004 2.155117522476896 2005 2.043885550014355 2006 1.9850099435149264 2007 1.9106763260982391 2008 1.867927937946565 2009 1.8351881537324315 2010 2.112431035339729 2011 2.093059905836929 2012 2.0728134662968656 2013 2.056136559720688 2014 2.0230484722413946 2015 2.0522742417852693 2016 2.556033944130778 2017 2.556094287928046 2018 2.502095504985425 2019 2.4602856084055658 2020 1.9911684023017906