Year	Percent
1998-01-01	28.400
1999-01-01	27.225
2000-01-01	27.625
2001-01-01	26.175
2002-01-01	26.475
2003-01-01	25.225
2004-01-01	26.875
2005-01-01	25.000
2006-01-01	24.125
2007-01-01	23.950
2008-01-01	23.475
2009-01-01	22.775
2010-01-01	20.100
2011-01-01	16.100
2012-01-01	13.000
2013-01-01	11.850
2014-01-01	13.300
2015-01-01	13.000
2016-01-01	13.000
2017-01-01	14.150