Year	Percent
1998-01-01	9.100
1999-01-01	7.975
2000-01-01	7.200
2001-01-01	6.875
2002-01-01	7.350
2003-01-01	7.500
2004-01-01	7.000
2005-01-01	6.450
2006-01-01	5.650
2007-01-01	4.925
2008-01-01	4.350
2009-01-01	7.050
2010-01-01	7.325
2011-01-01	6.650
2012-01-01	6.550
2013-01-01	6.900
2014-01-01	7.600
2015-01-01	7.900
2016-01-01	7.475
2017-01-01	7.250