Year % of total labor force 1991 40.91831443915991 1992 41.704253479242745 1993 41.72549343658514 1994 42.008164458739124 1995 42.45965856882627 1996 43.012989152538886 1997 43.61620662908636 1998 43.84901555108741 1999 44.8171684550474 2000 45.79035141615119 2001 46.16531434663968 2002 46.58800669957842 2003 45.96119775148188 2004 46.37499639497851 2005 47.11720684723929 2006 47.2019631795413 2007 48.12702821810606 2008 48.23167411647019 2009 48.71137794699077 2010 48.4426858796433 2011 48.83890394801011 2012 48.665627522476136 2013 49.21524081349223 2014 49.2269919002949 2015 49.54441582458226 2016 49.91944824681479 2017 49.71374592087937 2018 49.77119220366195 2019 49.88068154499052 2020 49.93307690142215 2021 50.2236084500983 2022 50.28455193353226 2023 50.28923627849322