Year	Percent
1991	10.454
1992	10.688
1993	10.942
1994	10.069
1995	9.775
1996	9.678
1997	9.528
1998	9.671
1999	9.23
2000	9.106
2001	8.175
2002	7.672
2003	7.803
2004	7.825
2005	7.153
2006	6.749
2007	7.239
2008	7.552
2009	7.483
2010	7.637
2011	7.449
2012	7.475
2013	8.244
2014	8.079
2015	8.251
2016	8.314
2017	8.05
2018	7.969
2019	7.913
2020	7.872
2021	7.837
2022	7.803