Year	Percent
1991	8.405
1992	8.295
1993	8.737
1994	8.66
1995	8.91
1996	9.224
1997	9.344
1998	8.832
1999	10.04
2000	9.518
2001	10.038
2002	10.114
2003	10.036
2004	9.849
2005	9.399
2006	8.909
2007	8.807
2008	9.561
2009	9.032
2010	9.042
2011	9.123
2012	8.996
2013	8.987
2014	8.962
2015	8.923
2016	8.875
2017	8.927
2018	8.928
2019	8.942
2020	8.953
2021	8.963
2022	8.973