Year	Percent
1998-01-01	4.525
1999-01-01	5.300
2000-01-01	4.675
2001-01-01	4.075
2002-01-01	4.400
2003-01-01	4.300
2004-01-01	4.150
2005-01-01	3.300
2006-01-01	2.950
2007-01-01	2.100
2008-01-01	2.850
2009-01-01	2.800
2010-01-01	3.025
2011-01-01	2.700
2012-01-01	4.175
2013-01-01	4.225
2014-01-01	4.425
2015-01-01	4.275
2016-01-01	4.775
2017-01-01	5.025