Year	Percent
1999-01-01	3.92
2000-01-01	3.85
2001-01-01	3.86
2002-01-01	3.86
2003-01-01	3.88
2004-01-01	3.65
2005-01-01	3.55
2006-01-01	3.43
2007-01-01	3.18
2008-01-01	3.55
2009-01-01	3.01
2010-01-01	2.91
2011-01-01	2.79
2012-01-01	2.57
2013-01-01	2.56
2014-01-01	2.58
2015-01-01	2.45
2016-01-01	2.43