Year	Percent
1997-01-01	1.25
1998-01-01	1.41
1999-01-01	1.51
2000-01-01	1.56
2001-01-01	1.53
2002-01-01	1.50
2003-01-01	1.51
2004-01-01	1.40
2005-01-01	1.38
2006-01-01	1.42
2007-01-01	1.46
2008-01-01	1.62
2009-01-01	1.91
2010-01-01	2.87
2011-01-01	2.50
2012-01-01	2.53
2013-01-01	2.32
2014-01-01	2.44
2015-01-01	2.64
2016-01-01	2.42