Year	Percent
1998-01-01	3.3000000000000000
1999-01-01	2.4000000000000000
2000-01-01	2.2000000000000000
2001-01-01	2.2000000000000000
2002-01-01	2.3000000000000000
2003-01-01	2.4000000000000000
2004-01-01	2.0000000000000000
2005-01-01	1.5000000000000000
2006-01-01	1.5000000000000000
2007-01-01	2.8000000000000000
2008-01-01	3.6000000000000000
2009-01-01	4.8000000000000000
2010-01-01	5.1994900000000000
2011-01-01	7.7264100000000004
2012-01-01	10.5162000000000000
2013-01-01	10.6624000000000000
2014-01-01	11.8944000000000000
2015-01-01	11.9618000000000000
2016-01-01	11.8383000000000000