Year	Percent
1998-01-01	9.1000000000000000
1999-01-01	8.3000000000000000
2000-01-01	8.3000000000000000
2001-01-01	8.3000000000000000
2002-01-01	8.3000000000000000
2003-01-01	8.3000000000000000
2004-01-01	8.3000000000000000
2005-01-01	8.3000000000000000
2006-01-01	3.0000000000000000
2007-01-01	2.5000000000000000
2008-01-01	2.0000000000000000
2009-01-01	3.3000000000000000
2010-01-01	2.7649800000000000
2011-01-01	2.8075799999999997
2012-01-01	3.6370800000000000
2013-01-01	4.1503700000000000
2014-01-01	4.9197500000000000
2015-01-01	7.1953200000000000
2016-01-01	7.7566000000000000