Year	% of total labor force (national estimate)
1992	6.733549903630841
1993	6.581657471718125
1995	8.443879939667651
1996	8.90136191061076
1997	8.4104723894737
1998	8.984218166714385
1999	9.736418084844617
2001	9.066143418722316
2002	9.790130237885581
2003	9.403245957760445
2004	8.452209286820288
2005	8.329874225916116
2006	7.2417500626591
2007	7.365420040882024
2008	6.756566822119753
2009	7.780527805849093
2011	6.590445846561789
2012	6.407890469834529
2013	6.1857775499602425
2014	6.001139517365835
2015	6.521144878510388
2016	7.603577349542861
2017	7.956782189022015
2018	7.970007454642692
2019	8.146857601171144
2020	10.519533852989634
2021	9.298371345710313
2022	6.9471600558449955
2023	6.402139224300108
