Year	Percent
1991	9.796
1992	9.572
1993	9.408
1994	9.696
1995	9.549
1996	9.438
1997	9.454
1998	9.378
1999	9.918
2000	9.745
2001	9.672
2002	9.706
2003	9.19
2004	9.398
2005	9.329
2006	9.305
2007	9.366
2008	9.264
2009	9.367
2010	9.406
2011	9.347
2012	9.608
2013	8.634
2014	8.92
2015	8.892
2016	9.019
2017	8.904
2018	8.994
2019	9.084
2020	9.184
2021	9.282
2022	9.376