Year	Percent
1998-01-01	11.950
1999-01-01	10.750
2000-01-01	10.600
2001-01-01	9.700
2002-01-01	9.075
2003-01-01	8.900
2004-01-01	8.925
2005-01-01	8.650
2006-01-01	8.150
2007-01-01	7.250
2008-01-01	6.725
2009-01-01	7.625
2010-01-01	7.700
2011-01-01	7.175
2012-01-01	7.150
2013-01-01	7.600
2014-01-01	8.050
2015-01-01	9.000
2016-01-01	8.675
2017-01-01	8.500