Year	Percent
1999-01-01	56.825
2000-01-01	58.275
2001-01-01	59.500
2002-01-01	59.550
2003-01-01	60.125
2004-01-01	54.900
2005-01-01	55.475
2006-01-01	55.600
2007-01-01	52.350
2008-01-01	52.350
2009-01-01	54.675
2010-01-01	55.625
2011-01-01	58.050
2012-01-01	61.825
2013-01-01	62.875
2014-01-01	63.425
2015-01-01	61.100
2016-01-01	63.175
2017-01-01	57.150