Year	Percent
1991	10.857
1992	10.168
1993	9.974
1994	10.319
1995	10.998
1996	11.8
1997	11.963
1998	11.963
1999	11.682
2000	11.382
2001	10.137
2002	10.295
2003	9.797
2004	9.768
2005	9.244
2006	9.273
2007	9.174
2008	8.228
2009	7.682
2010	7.605
2011	7.578
2012	7.682
2013	7.759
2014	7.197
2015	6.912
2016	6.952
2017	6.893
2018	6.76
2019	6.69
2020	6.642
2021	6.591
2022	6.539