Year	Percent
1997-01-01	5.7807500000000000
1998-01-01	1.8496099999999998
1999-01-01	6.4787400000000000
2000-01-01	10.1004000000000000
2001-01-01	10.2602000000000000
2002-01-01	7.0263399999999990
2003-01-01	7.1830399999999990
2004-01-01	6.6135500000000000
2005-01-01	7.9377500000000000
2006-01-01	6.1772000000000000
2007-01-01	6.1998900000000000
2008-01-01	6.3663500000000000
2009-01-01	5.0606400000000000
2010-01-01	4.7702100000000000
2011-01-01	4.9272599999999995
2012-01-01	4.4395900000000000
2013-01-01	4.3202000000000000
2014-01-01	4.0414600000000000
2015-01-01	4.4654800000000000
2016-01-01	3.7423400000000000