Year	Percent
1999-01-01	23.125
2000-01-01	23.825
2001-01-01	23.425
2002-01-01	23.675
2003-01-01	23.250
2004-01-01	23.050
2005-01-01	23.575
2006-01-01	23.550
2007-01-01	23.875
2008-01-01	23.600
2009-01-01	24.675
2010-01-01	25.775
2011-01-01	26.425
2012-01-01	27.375
2013-01-01	28.550
2014-01-01	28.225
2015-01-01	27.725
2016-01-01	26.475
2017-01-01	27.750