Year	Percent
1998-01-01	10.700
1999-01-01	9.150
2000-01-01	8.875
2001-01-01	9.425
2002-01-01	11.675
2003-01-01	14.575
2004-01-01	15.450
2005-01-01	16.225
2006-01-01	16.525
2007-01-01	16.700
2008-01-01	16.675
2009-01-01	20.325
2010-01-01	22.750
2011-01-01	30.225
2012-01-01	37.925
2013-01-01	38.100
2014-01-01	34.825
2015-01-01	31.950
2016-01-01	27.925
2017-01-01	23.875