Year	Percent
1998-01-01	12.000
1999-01-01	11.550
2000-01-01	10.700
2001-01-01	9.650
2002-01-01	9.100
2003-01-01	8.775
2004-01-01	8.100
2005-01-01	7.825
2006-01-01	6.875
2007-01-01	6.175
2008-01-01	6.800
2009-01-01	7.850
2010-01-01	8.450
2011-01-01	8.450
2012-01-01	10.800
2013-01-01	12.325
2014-01-01	12.875
2015-01-01	12.075
2016-01-01	11.875
2017-01-01	11.450