Year	Percent
1991	11.73354
1992	11.72907
1993	11.73185
1994	11.72424
1995	11.73789
1996	11.70689
1997	11.66848
1998	11.60357
1999	11.52746
2000	11.46936
2001	11.39219
2002	11.32139
2003	11.20095
2004	11.04193
2005	10.86861
2006	10.73757
2007	10.67451
2008	10.58001
2009	10.95297
2010	11.56677
2011	9.7926
2012	8.60559
2013	9.28792
2014	9.13969
2015	8.82358
2016	8.22367
2017	8.74416
2018	8.35869
2019	8.41306