Year	Percent
1998-01-01	26.400
1999-01-01	26.150
2000-01-01	25.875
2001-01-01	25.925
2002-01-01	25.650
2003-01-01	25.250
2004-01-01	25.025
2005-01-01	25.400
2006-01-01	25.450
2007-01-01	25.750
2008-01-01	25.700
2009-01-01	26.450
2010-01-01	26.900
2011-01-01	27.175
2012-01-01	26.275
2013-01-01	26.750
2014-01-01	26.425
2015-01-01	25.950
2016-01-01	25.200
2017-01-01	24.975