Year	Percent
1999-01-01	48.575
2000-01-01	48.725
2001-01-01	47.675
2002-01-01	48.725
2003-01-01	49.350
2004-01-01	50.575
2005-01-01	51.775
2006-01-01	52.125
2007-01-01	53.125
2008-01-01	53.550
2009-01-01	53.725
2010-01-01	54.575
2011-01-01	53.850
2012-01-01	54.000
2013-01-01	54.675
2014-01-01	55.175
2015-01-01	55.075
2016-01-01	54.725
2017-01-01	54.900