Year	Percent
1998-01-01	26.825
1999-01-01	26.225
2000-01-01	25.700
2001-01-01	24.925
2002-01-01	24.250
2003-01-01	23.725
2004-01-01	22.350
2005-01-01	22.575
2006-01-01	22.175
2007-01-01	22.475
2008-01-01	21.900
2009-01-01	22.800
2010-01-01	23.150
2011-01-01	23.175
2012-01-01	22.175
2013-01-01	22.875
2014-01-01	23.050
2015-01-01	23.250
2016-01-01	22.525
2017-01-01	22.150