Year Percent of total labor force 1997 12.26 1998 12.8 1999 13.3 2000 12.1 2001 12.2 2002 14.47 2003 16 2004 19.53 2005 21.83 2006 21.56 2007 18.8 2008 14.4 2009 16.9 2010 20 2011 23.6 2012 24.6 2013 23 2014 19.894 2015 18.231 2016 15.917 2017 14.051 2018 13.742 2019 13.449 2020 13.16 2021 12.875 2022 12.595 2023 12.319 2024 11.984