Year	Percent
1991	13.186
1992	13.378
1993	13.005
1994	12.787
1995	12.129
1996	11.899
1997	11.107
1998	10.859
1999	11.675
2000	11.078
2001	11.713
2002	11.438
2003	10.496
2004	9.585
2005	8.997
2006	8.902
2007	9.085
2008	8.85
2009	8.631
2010	9.034
2011	8.95
2012	8.89
2013	8.365
2014	8.248
2015	8.027
2016	8.424
2017	8.573
2018	8.477
2019	8.391
2020	8.315
2021	8.25
2022	8.183