Year	Percent
1999-01-01	69.250
2000-01-01	65.525
2001-01-01	64.575
2002-01-01	63.125
2003-01-01	61.075
2004-01-01	60.275
2005-01-01	57.675
2006-01-01	57.025
2007-01-01	57.900
2008-01-01	60.225
2009-01-01	58.550
2010-01-01	57.825
2011-01-01	56.325
2012-01-01	54.625
2013-01-01	51.000
2014-01-01	46.825
2015-01-01	42.200
2016-01-01	37.625
2017-01-01	35.500