Year Percent of total labor force 1999 4.345 2000 4.571 2001 4.617 2002 5.265 2003 5.562 2004 5.822 2005 6.051 2006 6.254 2007 5.645 2008 5.176 2009 5.377 2010 5.548 2011 5.772 2012 5.524 2013 5.568 2014 5.721 2015 5.591 2016 5.6 2017 6