Year	Percent
1998-01-01	4.35
1999-01-01	4.15
2000-01-01	4.00
2001-01-01	3.58
2002-01-01	3.48
2003-01-01	3.70
2004-01-01	3.75
2005-01-01	3.67
2006-01-01	4.02
2007-01-01	4.21
2008-01-01	2.80
2009-01-01	3.77
2010-01-01	3.90
2011-01-01	3.50
2012-01-01	4.20
2013-01-01	5.19
2014-01-01	5.08
2015-01-01	5.64
2016-01-01	6.52