Year	Percent
1999-01-01	9.400
2000-01-01	8.700
2001-01-01	5.650
2002-01-01	6.125
2003-01-01	6.100
2004-01-01	6.175
2005-01-01	5.700
2006-01-01	4.950
2007-01-01	5.000
2008-01-01	6.450
2009-01-01	11.350
2010-01-01	14.400
2011-01-01	15.375
2012-01-01	18.075
2013-01-01	20.275
2014-01-01	20.425
2015-01-01	18.525
2016-01-01	16.850
2017-01-01	14.850