Year	Percent
1999-01-01	58.300
2000-01-01	58.700
2001-01-01	57.775
2002-01-01	57.625
2003-01-01	58.100
2004-01-01	57.900
2005-01-01	58.325
2006-01-01	58.950
2007-01-01	58.750
2008-01-01	58.125
2009-01-01	57.850
2010-01-01	57.825
2011-01-01	58.325
2012-01-01	59.250
2013-01-01	60.150
2014-01-01	61.850
2015-01-01	63.100
2016-01-01	64.350
2017-01-01	65.150