Year	Percent
1998-01-01	11.500
1999-01-01	10.275
2000-01-01	9.875
2001-01-01	9.200
2002-01-01	9.175
2003-01-01	9.075
2004-01-01	8.875
2005-01-01	8.475
2006-01-01	7.775
2007-01-01	6.950
2008-01-01	6.425
2009-01-01	8.325
2010-01-01	8.500
2011-01-01	7.900
2012-01-01	7.800
2013-01-01	8.325
2014-01-01	8.825
2015-01-01	9.575
2016-01-01	8.975
2017-01-01	8.825