Year	Percent
1999-01-01	76.050
2000-01-01	76.250
2001-01-01	76.200
2002-01-01	75.875
2003-01-01	75.125
2004-01-01	75.675
2005-01-01	75.900
2006-01-01	77.375
2007-01-01	77.000
2008-01-01	77.850
2009-01-01	75.375
2010-01-01	73.350
2011-01-01	73.150
2012-01-01	72.575
2013-01-01	72.550
2014-01-01	72.800
2015-01-01	73.500
2016-01-01	74.850
2017-01-01	74.200