Year Percent of total labor force (Units) 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 5.600 2017 5.900 2018 6.025 2019 5.625 2020 7.650 2021 6.600 2022 5.600