Year	Percent
1998-01-01	36.825
1999-01-01	41.850
2000-01-01	42.250
2001-01-01	42.875
2002-01-01	41.050
2003-01-01	40.100
2004-01-01	39.450
2005-01-01	40.400
2006-01-01	42.600
2007-01-01	44.475
2008-01-01	44.300
2009-01-01	37.725
2010-01-01	37.650
2011-01-01	39.550
2012-01-01	40.925
2013-01-01	39.125
2014-01-01	39.775
2015-01-01	38.125
2016-01-01	40.075
2017-01-01	41.375