Year	Percent
1991	15.236
1992	16.046
1993	12.052
1994	11.985
1995	11.666
1996	11.236
1997	10.021
1998	9.545
1999	8.797
2000	9.174
2001	9.509
2002	9.736
2003	8.663
2004	8.683
2005	8.376
2006	8.268
2007	8.031
2008	9.502
2009	9.252
2010	9.12
2011	7.79
2012	7.884
2013	7.907
2014	8.007
2015	8.206
2016	8.217
2017	8.283
2018	8.157
2019	7.99
2020	7.862
2021	7.77
2022	7.655