Year	Percent
1999-01-01	23.050
2000-01-01	20.475
2001-01-01	15.225
2002-01-01	16.150
2003-01-01	15.825
2004-01-01	14.825
2005-01-01	12.000
2006-01-01	11.350
2007-01-01	10.675
2008-01-01	12.850
2009-01-01	18.125
2010-01-01	20.225
2011-01-01	21.825
2012-01-01	25.050
2013-01-01	26.675
2014-01-01	25.450
2015-01-01	23.550
2016-01-01	21.400
2017-01-01	19.050