Year	Percent
1999-01-01	57.600
2000-01-01	60.175
2001-01-01	61.175
2002-01-01	62.300
2003-01-01	62.875
2004-01-01	62.300
2005-01-01	62.925
2006-01-01	63.300
2007-01-01	62.775
2008-01-01	64.700
2009-01-01	63.625
2010-01-01	63.650
2011-01-01	63.550
2012-01-01	63.600
2013-01-01	63.325
2014-01-01	64.250
2015-01-01	66.225
2016-01-01	67.000
2017-01-01	67.825