Year	Percent
1998-01-01	13.000
1999-01-01	18.025
2000-01-01	18.100
2001-01-01	17.550
2002-01-01	16.875
2003-01-01	18.550
2004-01-01	21.025
2005-01-01	19.200
2006-01-01	17.500
2007-01-01	10.725
2008-01-01	9.850
2009-01-01	16.575
2010-01-01	18.350
2011-01-01	18.075
2012-01-01	19.525
2013-01-01	18.975
2014-01-01	15.825
2015-01-01	12.550
2016-01-01	10.475
2017-01-01	7.950