Year	Percent
1998-01-01	44.050
1999-01-01	43.700
2000-01-01	44.025
2001-01-01	44.400
2002-01-01	44.500
2003-01-01	44.575
2004-01-01	44.850
2005-01-01	44.425
2006-01-01	44.500
2007-01-01	45.175
2008-01-01	45.600
2009-01-01	45.425
2010-01-01	45.675
2011-01-01	45.350
2012-01-01	44.750
2013-01-01	43.675
2014-01-01	43.700
2015-01-01	43.175
2016-01-01	42.375
2017-01-01	41.825