Year	Percent
1999-01-01	61.600
2000-01-01	61.325
2001-01-01	60.350
2002-01-01	61.125
2003-01-01	61.550
2004-01-01	62.375
2005-01-01	62.350
2006-01-01	62.600
2007-01-01	63.900
2008-01-01	64.025
2009-01-01	65.125
2010-01-01	64.800
2011-01-01	65.875
2012-01-01	65.050
2013-01-01	66.350
2014-01-01	67.725
2015-01-01	67.200
2016-01-01	69.300
2017-01-01	69.350