Year % of total labor force 1991 18.770494814999054 1992 19.089110441767616 1993 19.287396696884276 1994 19.951020471328018 1995 20.6697352280033 1996 19.144180136355978 1997 17.751264404467708 1998 16.47851441880379 1999 18.345785884009878 2000 20.378884832578674 2001 20.12234131474718 2002 19.87628436869537 2003 19.640485099220232 2004 18.633635089141656 2005 17.65194344194354 2006 16.702505489645283 2007 15.983821574726717 2008 15.649285954855088 2009 15.323262346282363 2010 15.14626973012472 2011 17.15505649581035 2012 17.18555490689309 2013 17.24913292046308 2014 17.5432902860103 2015 17.794571968799506 2016 17.97870034333984 2017 18.13033921235555 2018 18.24106614035042 2019 18.313468435392334 2020 18.19410649361626 2021 18.41223553005319 2022 18.279863847399326 2023 18.44069387727308