Year	Percent
1998-01-01	17.250
1999-01-01	18.300
2000-01-01	17.225
2001-01-01	16.250
2002-01-01	15.800
2003-01-01	15.125
2004-01-01	16.325
2005-01-01	15.450
2006-01-01	13.775
2007-01-01	12.925
2008-01-01	11.550
2009-01-01	13.300
2010-01-01	16.350
2011-01-01	21.525
2012-01-01	28.225
2013-01-01	31.375
2014-01-01	30.175
2015-01-01	28.875
2016-01-01	28.125
2017-01-01	26.100