Year	Percent
1998-01-01	2.800
1999-01-01	3.450
2000-01-01	3.325
2001-01-01	3.200
2002-01-01	3.700
2003-01-01	3.700
2004-01-01	5.100
2005-01-01	4.500
2006-01-01	4.700
2007-01-01	4.075
2008-01-01	5.050
2009-01-01	5.150
2010-01-01	4.350
2011-01-01	4.925
2012-01-01	5.150
2013-01-01	5.850
2014-01-01	5.850
2015-01-01	6.675
2016-01-01	6.275
2017-01-01	5.525