Year	Percent
1999-01-01	6.275
2000-01-01	5.650
2001-01-01	4.975
2002-01-01	5.425
2003-01-01	5.575
2004-01-01	6.125
2005-01-01	7.425
2006-01-01	7.950
2007-01-01	7.775
2008-01-01	8.025
2009-01-01	9.775
2010-01-01	10.775
2011-01-01	11.075
2012-01-01	10.675
2013-01-01	10.150
2014-01-01	7.950
2015-01-01	7.075
2016-01-01	5.125
2017-01-01	4.600