Year	Percent
1998-01-01	11.400
1999-01-01	10.200
2000-01-01	9.775
2001-01-01	9.125
2002-01-01	9.075
2003-01-01	9.025
2004-01-01	8.825
2005-01-01	8.375
2006-01-01	7.725
2007-01-01	6.850
2008-01-01	6.375
2009-01-01	8.225
2010-01-01	8.400
2011-01-01	7.775
2012-01-01	7.675
2013-01-01	8.175
2014-01-01	8.625
2015-01-01	9.375
2016-01-01	8.800
2017-01-01	8.625