Year	Percent
1998-01-01	16.425
1999-01-01	15.850
2000-01-01	14.575
2001-01-01	13.050
2002-01-01	12.300
2003-01-01	11.700
2004-01-01	10.550
2005-01-01	10.100
2006-01-01	8.825
2007-01-01	7.875
2008-01-01	8.550
2009-01-01	9.275
2010-01-01	9.675
2011-01-01	9.600
2012-01-01	11.925
2013-01-01	13.150
2014-01-01	13.925
2015-01-01	12.825
2016-01-01	12.900
2017-01-01	12.550