Year	Percent
1998-01-01	4.0000000000000000
1999-01-01	4.1000000000000000
2000-01-01	2.8000000000000000
2001-01-01	2.7000000000000000
2002-01-01	3.0000000000000000
2003-01-01	3.1000000000000000
2004-01-01	3.1000000000000000
2005-01-01	2.7000000000000000
2006-01-01	3.3000000000000000
2007-01-01	4.1000000000000000
2008-01-01	3.3000000000000000
2009-01-01	4.6000000000000000
2010-01-01	4.9653100000000000
2011-01-01	4.5998000000000000
2012-01-01	5.7605800000000000
2013-01-01	6.3899400000000000
2014-01-01	6.6273100000000005
2015-01-01	6.7830300000000000
2016-01-01	6.9011900000000000