Year % of total labor force 1991 24.28495162135418 1992 25.053074096820342 1993 25.91346497705412 1994 26.755142907957925 1995 27.568403616990935 1996 28.427790164918747 1997 28.536118802138482 1998 28.672134200998823 1999 28.775556474155735 2000 28.813666513371405 2001 28.844866847012213 2002 28.871293020148332 2003 28.900353679331165 2004 28.94388244385973 2005 28.98713559345322 2006 29.006640403233035 2007 29.00886072445898 2008 29.01561141466731 2009 29.027260568739738 2010 28.99543697468319 2011 28.978004858890017 2012 29.169448132393676 2013 29.3029184022646 2014 29.454720257142448 2015 29.57863688907273 2016 29.691032093431108 2017 29.824478385201836 2018 29.941834448907706 2019 30.009423077329174 2020 29.979065948230595 2021 30.107164486445736 2022 29.822048679199526 2023 29.571055282594155