Year	Percent
2000-01-01	75.275
2001-01-01	76.325
2002-01-01	76.050
2003-01-01	75.925
2004-01-01	76.850
2005-01-01	77.950
2006-01-01	78.275
2007-01-01	78.600
2008-01-01	77.325
2009-01-01	72.225
2010-01-01	70.150
2011-01-01	69.150
2012-01-01	69.400
2013-01-01	71.275
2014-01-01	72.950
2015-01-01	74.600
2016-01-01	75.725
2017-01-01	77.925