Year	Percent
1998-01-01	5.925
1999-01-01	6.650
2000-01-01	6.200
2001-01-01	5.950
2002-01-01	5.750
2003-01-01	5.375
2004-01-01	5.650
2005-01-01	5.450
2006-01-01	5.000
2007-01-01	4.725
2008-01-01	4.550
2009-01-01	6.500
2010-01-01	9.475
2011-01-01	14.575
2012-01-01	21.000
2013-01-01	23.700
2014-01-01	22.950
2015-01-01	20.875
2016-01-01	18.450
2017-01-01	16.675