Year	Percent
1999-01-01	56.250
2000-01-01	56.375
2001-01-01	55.125
2002-01-01	56.250
2003-01-01	56.850
2004-01-01	58.200
2005-01-01	59.500
2006-01-01	59.525
2007-01-01	60.450
2008-01-01	60.775
2009-01-01	60.925
2010-01-01	61.825
2011-01-01	61.100
2012-01-01	61.350
2013-01-01	62.275
2014-01-01	62.975
2015-01-01	62.925
2016-01-01	62.850
2017-01-01	63.175