Year	Percent
1998-01-01	11.450
1999-01-01	12.325
2000-01-01	11.550
2001-01-01	10.950
2002-01-01	10.550
2003-01-01	9.975
2004-01-01	10.750
2005-01-01	10.150
2006-01-01	9.175
2007-01-01	8.525
2008-01-01	7.875
2009-01-01	9.775
2010-01-01	12.925
2011-01-01	18.125
2012-01-01	24.700
2013-01-01	27.675
2014-01-01	26.700
2015-01-01	25.125
2016-01-01	23.725
2017-01-01	21.650