Year	Percent
1998-01-01	2.70000
1999-01-01	2.70000
2000-01-01	2.80000
2001-01-01	2.90000
2002-01-01	3.00000
2003-01-01	2.60000
2004-01-01	2.30000
2005-01-01	2.00000
2006-01-01	1.70000
2007-01-01	1.40000
2008-01-01	1.70000
2009-01-01	3.10000
2010-01-01	2.79861
2011-01-01	3.30230
2012-01-01	3.73826
2013-01-01	4.24498
2014-01-01	4.17569
2015-01-01	3.78935
2016-01-01	3.47335