Year	Percent
1999-01-01	25.075
2000-01-01	25.350
2001-01-01	26.050
2002-01-01	26.500
2003-01-01	24.750
2004-01-01	25.425
2005-01-01	25.200
2006-01-01	24.725
2007-01-01	24.950
2008-01-01	25.025
2009-01-01	23.225
2010-01-01	23.100
2011-01-01	24.200
2012-01-01	22.675
2013-01-01	21.875
2014-01-01	21.825
2015-01-01	21.675
2016-01-01	21.425
2017-01-01	20.875