Year	Percent
1991	9.165
1992	8.447
1993	8.405
1994	8.475
1995	8.024
1996	7.713
1997	7.587
1998	8.154
1999	7.751
2000	7.212
2001	7.359
2002	6.944
2003	7.024
2004	6.874
2005	6.652
2006	6.518
2007	6.743
2008	6.609
2009	6.447
2010	6.871
2011	6.482
2012	6.448
2013	6.504
2014	6.51
2015	6.272
2016	6.083
2017	6.46
2018	6.323
2019	6.172
2020	6.071
2021	5.972
2022	5.872