Year	Percent
1998-01-01	13.000
1999-01-01	12.275
2000-01-01	12.125
2001-01-01	12.025
2002-01-01	12.000
2003-01-01	12.550
2004-01-01	12.600
2005-01-01	12.300
2006-01-01	12.175
2007-01-01	11.975
2008-01-01	11.400
2009-01-01	11.750
2010-01-01	12.500
2011-01-01	12.350
2012-01-01	12.700
2013-01-01	13.250
2014-01-01	13.375
2015-01-01	13.375
2016-01-01	13.725
2017-01-01	13.225