Year	Percent
1998-01-01	58.250
1999-01-01	56.775
2000-01-01	54.125
2001-01-01	49.700
2002-01-01	47.925
2003-01-01	46.250
2004-01-01	45.100
2005-01-01	43.375
2006-01-01	41.475
2007-01-01	41.225
2008-01-01	40.325
2009-01-01	40.875
2010-01-01	39.825
2011-01-01	39.125
2012-01-01	37.750
2013-01-01	37.075
2014-01-01	36.250
2015-01-01	34.775
2016-01-01	33.600
2017-01-01	32.150