Year % of total labor force (national estimate) 2000 7.54 2001 7.84 2002 12.55 2003 9.92 2004 8.53 2005 8.11 2006 8.27 2007 8.1 2008 8.22 2009 8.41 2010 6.007 2011 5.824 2012 4.67 2013 4.296 2014 4.051 2015 3.364 2016 3.249 2017 2.655 2018 3.673 2019 4.252 2020 4.63 2021 4.096