Year	Percent of total labor force
1996	12.715
1997	7.551
1998	12.381
1999	12.628
2000	10.346
2001	11.148
2002	13.5
2003	12.7
2004	13.9
2005	15.1
2006	15.4
2007	17.4
2008	17.9
2009	18.3
2010	17.4
2011	17.3
2012	17.2
2013	16.9
2014	14.6
2015	14.1
2016	14
2017	13.9