Year	Percent
1998-01-01	4.00
1999-01-01	4.10
2000-01-01	4.20
2001-01-01	4.40
2002-01-01	4.10
2003-01-01	4.20
2004-01-01	4.00
2005-01-01	4.10
2006-01-01	4.30
2007-01-01	4.30
2008-01-01	4.50
2009-01-01	4.80
2010-01-01	4.30
2011-01-01	4.36
2012-01-01	4.73
2013-01-01	5.45
2014-01-01	5.61
2015-01-01	5.94
2016-01-01	5.98