Year	Percent
1998-01-01	11.3000000000000000
1999-01-01	8.9000000000000000
2000-01-01	5.8000000000000000
2001-01-01	5.1000000000000000
2002-01-01	3.7000000000000000
2003-01-01	3.2000000000000000
2004-01-01	2.5000000000000000
2005-01-01	1.5000000000000000
2006-01-01	1.8000000000000000
2007-01-01	2.3000000000000000
2008-01-01	3.0000000000000000
2009-01-01	2.8000000000000000
2010-01-01	2.0432900000000003
2011-01-01	2.1157200000000000
2012-01-01	2.4441599999999997
2013-01-01	3.2432000000000000
2014-01-01	3.0367400000000000
2015-01-01	2.5232099999999997
2016-01-01	2.2874500000000000