Year	Percent
1998-01-01	1.8740800000000000
1999-01-01	1.8862299999999999
2000-01-01	1.7798500000000000
2001-01-01	1.6561599999999999
2002-01-01	1.7880500000000000
2003-01-01	1.5430900000000000
2004-01-01	1.4257400000000000
2005-01-01	1.4725500000000000
2006-01-01	1.3450700000000000
2007-01-01	1.3240600000000000
2008-01-01	1.3068000000000000
2009-01-01	1.3369600000000000
2010-01-01	1.3642000000000000
2011-01-01	1.3582400000000000
2012-01-01	1.3691300000000000
2013-01-01	1.3644000000000000
2014-01-01	1.4352900000000000
2015-01-01	1.5302200000000001