Year	Percent
1999-01-01	78.825
2000-01-01	77.325
2001-01-01	76.325
2002-01-01	75.150
2003-01-01	73.825
2004-01-01	72.450
2005-01-01	70.100
2006-01-01	68.850
2007-01-01	67.250
2008-01-01	65.750
2009-01-01	62.950
2010-01-01	61.550
2011-01-01	58.225
2012-01-01	56.125
2013-01-01	54.800
2014-01-01	53.100
2015-01-01	50.600
2016-01-01	48.300
2017-01-01	48.200