Year	Percent
1999-01-01	17.175
2000-01-01	14.625
2001-01-01	15.725
2002-01-01	15.050
2003-01-01	15.575
2004-01-01	13.850
2005-01-01	14.475
2006-01-01	11.775
2007-01-01	9.400
2008-01-01	9.900
2009-01-01	13.775
2010-01-01	15.250
2011-01-01	15.050
2012-01-01	20.150
2013-01-01	20.125
2014-01-01	19.475
2015-01-01	17.725
2016-01-01	15.675
2017-01-01	10.125