Year	Percent
1999-01-01	40.750
2000-01-01	44.575
2001-01-01	45.500
2002-01-01	44.950
2003-01-01	45.000
2004-01-01	43.300
2005-01-01	42.000
2006-01-01	42.050
2007-01-01	40.575
2008-01-01	40.475
2009-01-01	40.500
2010-01-01	41.725
2011-01-01	40.800
2012-01-01	40.750
2013-01-01	41.225
2014-01-01	41.975
2015-01-01	42.550
2016-01-01	42.525
2017-01-01	43.925