Year	% of total labor force (national estimate)
1991	5.91
1993	7.22
1994	5.74
1995	4.94
1996	5.1
1997	4.14
1998	4.17
2001	7.54
2002	5.37
2003	3.61
2004	3.45
2005	3.54
2006	2.62
2007	3.83
2008	3.97
2009	6.04
2010	6.68
2011	6.78
2012	6.21
2013	6.27
2014	4.7
2015	4.24