Year	Percent
1998-01-01	6.600
1999-01-01	5.475
2000-01-01	5.275
2001-01-01	5.300
2002-01-01	6.375
2003-01-01	7.650
2004-01-01	7.950
2005-01-01	9.100
2006-01-01	9.425
2007-01-01	10.050
2008-01-01	9.275
2009-01-01	10.700
2010-01-01	12.500
2011-01-01	13.525
2012-01-01	16.125
2013-01-01	17.000
2014-01-01	14.775
2015-01-01	13.100
2016-01-01	11.475
2017-01-01	9.600