Year	Percent
2000-01-01	52.850
2001-01-01	52.575
2002-01-01	52.025
2003-01-01	53.025
2004-01-01	53.150
2005-01-01	53.600
2006-01-01	54.775
2007-01-01	54.075
2008-01-01	54.750
2009-01-01	54.700
2010-01-01	55.100
2011-01-01	55.650
2012-01-01	55.425
2013-01-01	55.425
2014-01-01	54.600
2015-01-01	55.925
2016-01-01	56.375
2017-01-01	57.050