Year	Percent
2001-01-01	50.050
2002-01-01	49.075
2003-01-01	47.725
2004-01-01	47.150
2005-01-01	49.875
2006-01-01	51.325
2007-01-01	52.225
2008-01-01	52.850
2009-01-01	51.025
2010-01-01	51.600
2011-01-01	52.975
2012-01-01	52.575
2013-01-01	54.500
2014-01-01	55.475
2015-01-01	55.150
2016-01-01	54.825
2017-01-01	54.725