Year Percent of total labor force (Units) 1999 14.525 2000 14.008 2001 13.358 2002 15.996 2003 18.188 2004 15.067 2005 12.242 2006 9.958 2007 8.492 2008 7.354 2009 7.879 2010 8.508 2011 8.204 2012 7.823 2013 7.470 2014 6.700 2015 7.400 2016 20.863 2017 27.886 2018 35.554