Year	Percent
1991	12.519
1992	12.259
1993	11.217
1994	11.031
1995	10.774
1996	10.044
1997	9.784
1998	9.243
1999	8.96
2000	8.302
2001	7.955
2002	7.722
2003	8.16
2004	7.801
2005	7.456
2006	7.801
2007	7.407
2008	7.373
2009	7.336
2010	7.621
2011	7.793
2012	7.682
2013	7.749
2014	8.179
2015	8.238
2016	8.461
2017	8.418
2018	8.378
2019	8.342
2020	8.308
2021	8.275
2022	8.248