Year	Percent
1991	11.737
1992	11.749
1993	11.553
1994	11.856
1995	11.445
1996	11.272
1997	11.196
1998	10.904
1999	11.589
2000	10.367
2001	10.373
2002	9.894
2003	10.117
2004	11.25
2005	8.95
2006	8.944
2007	8.786
2008	9.595
2009	10.284
2010	8.698
2011	8.864
2012	8.376
2013	8.059
2014	8.953
2015	9.652
2016	8.377
2017	8.416
2018	8.361
2019	8.266
2020	8.171
2021	8.084
2022	8.002