Year	Percent
1998-01-01	30.900
1999-01-01	28.925
2000-01-01	28.125
2001-01-01	27.550
2002-01-01	27.175
2003-01-01	27.825
2004-01-01	27.975
2005-01-01	27.150
2006-01-01	26.725
2007-01-01	26.175
2008-01-01	26.050
2009-01-01	26.475
2010-01-01	27.525
2011-01-01	27.350
2012-01-01	26.575
2013-01-01	26.575
2014-01-01	26.100
2015-01-01	25.550
2016-01-01	25.925
2017-01-01	25.100