Year	Percent
1991	8.636
1992	9.401
1993	10.207
1994	10.224
1995	9.811
1996	9.667
1997	8.282
1998	9.177
1999	9.36
2000	8.073
2001	9.396
2002	9.393
2003	9.046
2004	10.387
2005	12.206
2006	12.034
2007	12.064
2008	12.11
2009	12.189
2010	12.114
2011	12.086
2012	12.01
2013	11.924
2014	11.905
2015	11.926
2016	11.937
2017	11.95
2018	11.942
2019	11.932
2020	11.92
2021	11.907
2022	11.893