Year	Percent
1998-01-01	39.525
1999-01-01	37.500
2000-01-01	36.725
2001-01-01	36.350
2002-01-01	35.950
2003-01-01	36.525
2004-01-01	36.675
2005-01-01	35.850
2006-01-01	35.350
2007-01-01	34.925
2008-01-01	34.850
2009-01-01	35.275
2010-01-01	36.275
2011-01-01	36.475
2012-01-01	36.200
2013-01-01	36.600
2014-01-01	36.525
2015-01-01	36.250
2016-01-01	36.850
2017-01-01	36.500