Year	Percent
1998-01-01	11.050
1999-01-01	9.825
2000-01-01	9.150
2001-01-01	8.725
2002-01-01	9.200
2003-01-01	9.275
2004-01-01	8.850
2005-01-01	8.275
2006-01-01	7.500
2007-01-01	6.625
2008-01-01	6.150
2009-01-01	9.000
2010-01-01	9.275
2011-01-01	8.550
2012-01-01	8.450
2013-01-01	9.025
2014-01-01	9.575
2015-01-01	10.125
2016-01-01	9.250
2017-01-01	9.100