Year	Percent
1998-01-01	34.575
1999-01-01	32.400
2000-01-01	32.675
2001-01-01	30.500
2002-01-01	31.250
2003-01-01	30.450
2004-01-01	32.175
2005-01-01	29.950
2006-01-01	29.450
2007-01-01	29.100
2008-01-01	28.250
2009-01-01	27.300
2010-01-01	24.175
2011-01-01	19.375
2012-01-01	16.100
2013-01-01	14.575
2014-01-01	15.775
2015-01-01	15.150
2016-01-01	14.700
2017-01-01	15.875