Year	Percent
1999-01-01	42.500
2000-01-01	41.750
2001-01-01	39.450
2002-01-01	39.600
2003-01-01	36.725
2004-01-01	36.100
2005-01-01	37.250
2006-01-01	36.875
2007-01-01	38.950
2008-01-01	40.075
2009-01-01	39.250
2010-01-01	38.175
2011-01-01	36.800
2012-01-01	35.625
2013-01-01	35.025
2014-01-01	33.550
2015-01-01	32.375
2016-01-01	29.400
2017-01-01	28.425