Year % of total labor force 1991 31.161291594385744 1992 31.806003003181903 1993 32.20973643792856 1994 32.21423364859561 1995 32.335629754354954 1996 32.48732267664558 1997 32.842539201886055 1998 33.08285334113108 1999 33.28722643159405 2000 33.41742580918216 2001 32.832139327416535 2002 34.06275920390572 2003 33.915490143348535 2004 33.80480141104599 2005 34.528048280118476 2006 34.846056006902984 2007 34.65525362160461 2008 35.82866154539711 2009 34.634291886829374 2010 36.31231353086381 2011 37.14346050193071 2012 37.67787910829148 2013 37.71527771876201 2014 37.820000171090626 2015 38.58194536160638 2016 38.870624459936664 2017 39.10921799324269 2018 39.27092570013572 2019 40.16052606510802 2020 39.18803788759747 2021 40.378877422010525 2022 39.91716542816125 2023 40.633502786249586