Year	Percent
1998-01-01	16.100
1999-01-01	15.850
2000-01-01	15.175
2001-01-01	14.750
2002-01-01	14.675
2003-01-01	14.100
2004-01-01	13.675
2005-01-01	13.000
2006-01-01	12.325
2007-01-01	12.300
2008-01-01	12.025
2009-01-01	12.200
2010-01-01	11.300
2011-01-01	11.625
2012-01-01	11.525
2013-01-01	11.725
2014-01-01	11.400
2015-01-01	11.225
2016-01-01	10.850
2017-01-01	10.425