Year	Percent
1991	11.752
1992	11.093
1993	11.747
1994	12.013
1995	11.669
1996	11.265
1997	11.11
1998	11.085
1999	10.643
2000	10.265
2001	10.151
2002	10.179
2003	8.914
2004	7.406
2005	7.404
2006	7.036
2007	7.05
2008	6.709
2009	6.987
2010	6.948
2011	6.994
2012	8.134
2013	8.569
2014	9.25
2015	9.236
2016	8.123
2017	8.161
2018	8.02
2019	7.825
2020	7.598
2021	7.373
2022	7.137