Year	Percent
1998-01-01	11.950
1999-01-01	10.675
2000-01-01	10.600
2001-01-01	9.675
2002-01-01	9.050
2003-01-01	8.875
2004-01-01	8.925
2005-01-01	8.625
2006-01-01	8.050
2007-01-01	7.150
2008-01-01	6.675
2009-01-01	7.575
2010-01-01	7.625
2011-01-01	7.100
2012-01-01	7.025
2013-01-01	7.500
2014-01-01	7.950
2015-01-01	8.825
2016-01-01	8.575
2017-01-01	8.375