Year	Percent
1997-01-01	1.64
1998-01-01	0.99
1999-01-01	1.06
2000-01-01	1.06
2001-01-01	1.06
2002-01-01	1.06
2003-01-01	1.06
2004-01-01	1.06
2005-01-01	3.75
2006-01-01	3.50
2007-01-01	3.29
2008-01-01	3.09
2009-01-01	3.27
2010-01-01	3.46
2011-01-01	3.81
2012-01-01	3.76
2013-01-01	3.88
2014-01-01	4.07
2015-01-01	4.24
2016-01-01	4.40