Year	Percent
1999-01-01	28.200
2000-01-01	29.125
2001-01-01	29.700
2002-01-01	29.350
2003-01-01	27.350
2004-01-01	27.800
2005-01-01	27.475
2006-01-01	27.575
2007-01-01	27.475
2008-01-01	27.400
2009-01-01	25.350
2010-01-01	25.225
2011-01-01	26.000
2012-01-01	25.250
2013-01-01	23.625
2014-01-01	23.200
2015-01-01	23.350
2016-01-01	22.750
2017-01-01	22.700