Year	Percent
1999-01-01	54.600
2000-01-01	54.225
2001-01-01	54.575
2002-01-01	54.225
2003-01-01	53.100
2004-01-01	53.025
2005-01-01	52.225
2006-01-01	51.775
2007-01-01	52.225
2008-01-01	52.450
2009-01-01	52.300
2010-01-01	51.175
2011-01-01	50.900
2012-01-01	49.750
2013-01-01	49.500
2014-01-01	47.875
2015-01-01	46.800
2016-01-01	45.925
2017-01-01	45.425