Year	Percent
1999-01-01	71.125
2000-01-01	71.625
2001-01-01	72.025
2002-01-01	71.700
2003-01-01	70.525
2004-01-01	71.575
2005-01-01	71.900
2006-01-01	73.450
2007-01-01	73.175
2008-01-01	74.075
2009-01-01	72.700
2010-01-01	71.100
2011-01-01	70.400
2012-01-01	69.975
2013-01-01	70.050
2014-01-01	69.800
2015-01-01	70.350
2016-01-01	72.000
2017-01-01	71.525