Year	Percent
1991	10.226
1992	11.112
1993	11.031
1994	11.198
1995	11.078
1996	12.118
1997	11.281
1998	10.647
1999	10.36
2000	9.123
2001	9.245
2002	9.393
2003	8.629
2004	8.854
2005	9.084
2006	8.77
2007	9.68
2008	9.324
2009	10.139
2010	9.669
2011	9.455
2012	8.624
2013	9.938
2014	10.248
2015	9.831
2016	10.138
2017	9.739
2018	9.334
2019	9.041
2020	8.804
2021	8.609
2022	8.45