Year	Percent
2001-01-01	50.075
2002-01-01	49.700
2003-01-01	48.250
2004-01-01	47.275
2005-01-01	50.800
2006-01-01	51.875
2007-01-01	52.725
2008-01-01	53.075
2009-01-01	50.975
2010-01-01	51.325
2011-01-01	52.800
2012-01-01	53.450
2013-01-01	55.150
2014-01-01	56.050
2015-01-01	56.525
2016-01-01	55.550
2017-01-01	55.375