Year	Percent
1998-01-01	41.000
1999-01-01	40.425
2000-01-01	39.875
2001-01-01	39.400
2002-01-01	38.925
2003-01-01	38.500
2004-01-01	37.200
2005-01-01	37.525
2006-01-01	37.350
2007-01-01	37.600
2008-01-01	37.100
2009-01-01	37.725
2010-01-01	37.975
2011-01-01	37.950
2012-01-01	36.525
2013-01-01	36.650
2014-01-01	36.050
2015-01-01	35.950
2016-01-01	35.050
2017-01-01	34.550