Year	Percent
1999-01-01	41.625
2000-01-01	41.900
2001-01-01	41.325
2002-01-01	41.575
2003-01-01	42.500
2004-01-01	42.475
2005-01-01	43.100
2006-01-01	43.400
2007-01-01	42.975
2008-01-01	42.750
2009-01-01	42.850
2010-01-01	43.775
2011-01-01	43.975
2012-01-01	44.975
2013-01-01	45.125
2014-01-01	46.450
2015-01-01	47.375
2016-01-01	48.050
2017-01-01	48.375