Year	Percent
1991	9.531
1992	9.287
1993	11.259
1994	11.318
1995	11.248
1996	10.685
1997	10.859
1998	11.206
1999	11.479
2000	11.458
2001	11.559
2002	11.509
2003	11.539
2004	11.473
2005	11.441
2006	11.184
2007	10.381
2008	10.409
2009	10.975
2010	11.125
2011	10.777
2012	10.887
2013	10.905
2014	11.086
2015	11.12
2016	11.275
2017	11.27
2018	11.277
2019	11.317
2020	11.337
2021	11.397
2022	11.485