Year	Percent
1991	9.078
1992	8.775
1993	8.735
1994	9.388
1995	9.187
1996	9.114
1997	8.96
1998	8.644
1999	8.387
2000	8.414
2001	8.297
2002	8.209
2003	8.269
2004	8.185
2005	7.98
2006	7.94
2007	7.789
2008	7.503
2009	7.649
2010	7.715
2011	7.564
2012	7.674
2013	7.59
2014	7.4
2015	7.344
2016	7.245
2017	7.184
2018	7.155
2019	7.08
2020	7.043
2021	7.014
2022	6.989