Year % of total labor force 1991 3.455619052555646 1992 2.9186124082721814 1993 2.8120581051549043 1994 3.0922296135099514 1995 7.430607415003139 1996 7.241801246445988 1997 7.13418076679612 1998 6.838666509229741 1999 6.6498559983902 2000 6.391934102777476 2001 6.132910586792256 2002 5.80305701711763 2003 5.608877752674701 2004 5.033388141337539 2005 4.548664208943974 2006 3.735223749732145 2007 3.4032431115672654 2008 3.1124988123359794 2009 2.9278259312698127 2010 2.809053640510422 2011 2.840490269204327 2012 2.7837779844074104 2013 2.6924790454290117 2014 2.6204801430625952 2015 2.5319947330345944 2016 2.426557966180316 2017 2.269808559567542 2018 2.2310042191543333 2019 2.1980361125764682 2020 2.2612721441025427