Year	Percent
1998-01-01	3.575
1999-01-01	3.900
2000-01-01	3.600
2001-01-01	3.150
2002-01-01	3.675
2003-01-01	4.700
2004-01-01	5.850
2005-01-01	6.850
2006-01-01	7.250
2007-01-01	7.100
2008-01-01	7.275
2009-01-01	8.225
2010-01-01	9.925
2011-01-01	11.925
2012-01-01	14.500
2013-01-01	14.675
2014-01-01	15.200
2015-01-01	13.950
2016-01-01	12.650
2017-01-01	9.000