Year	Percent
1999-01-01	15.300
2000-01-01	14.700
2001-01-01	14.550
2002-01-01	13.375
2003-01-01	12.700
2004-01-01	14.550
2005-01-01	14.275
2006-01-01	13.875
2007-01-01	13.475
2008-01-01	13.500
2009-01-01	13.025
2010-01-01	12.850
2011-01-01	12.375
2012-01-01	11.850
2013-01-01	11.675
2014-01-01	12.000
2015-01-01	11.975
2016-01-01	11.625
2017-01-01	11.350
