Year	Percent
1999-01-01	16.350
2000-01-01	18.775
2001-01-01	19.325
2002-01-01	18.675
2003-01-01	17.575
2004-01-01	18.250
2005-01-01	16.250
2006-01-01	13.400
2007-01-01	11.150
2008-01-01	9.550
2009-01-01	12.050
2010-01-01	14.425
2011-01-01	13.675
2012-01-01	14.000
2013-01-01	14.275
2014-01-01	13.200
2015-01-01	11.525
2016-01-01	9.725
2017-01-01	8.200