Year	Percent
1998-01-01	40.375
1999-01-01	40.950
2000-01-01	40.525
2001-01-01	40.125
2002-01-01	41.300
2003-01-01	43.125
2004-01-01	41.700
2005-01-01	43.600
2006-01-01	44.150
2007-01-01	44.150
2008-01-01	44.425
2009-01-01	44.375
2010-01-01	45.200
2011-01-01	43.100
2012-01-01	42.125
2013-01-01	42.450
2014-01-01	41.100
2015-01-01	41.600
2016-01-01	44.875
2017-01-01	46.725