Year	Percent
1998-01-01	42.175
1999-01-01	42.575
2000-01-01	43.200
2001-01-01	43.925
2002-01-01	44.475
2003-01-01	44.875
2004-01-01	45.625
2005-01-01	45.300
2006-01-01	45.750
2007-01-01	45.800
2008-01-01	45.800
2009-01-01	44.700
2010-01-01	44.175
2011-01-01	44.125
2012-01-01	43.850
2013-01-01	42.850
2014-01-01	42.850
2015-01-01	43.150
2016-01-01	43.700
2017-01-01	44.225