Year	Percent
1998-01-01	22.900
1999-01-01	22.100
2000-01-01	21.875
2001-01-01	22.125
2002-01-01	21.225
2003-01-01	20.200
2004-01-01	18.850
2005-01-01	18.525
2006-01-01	18.050
2007-01-01	18.175
2008-01-01	18.050
2009-01-01	17.250
2010-01-01	16.750
2011-01-01	16.875
2012-01-01	16.250
2013-01-01	16.125
2014-01-01	15.650
2015-01-01	14.625
2016-01-01	14.525
2017-01-01	15.000