Year	Percent
1997-01-01	1.6945599999999998
1998-01-01	1.2261500000000000
1999-01-01	0.3464570000000000
2000-01-01	0.2813280000000000
2001-01-01	0.2604100000000000
2002-01-01	0.4349580000000000
2003-01-01	0.3105120000000000
2004-01-01	0.2851770000000000
2005-01-01	0.2912020000000000
2006-01-01	1.6373799999999998
2007-01-01	1.8215200000000000
2008-01-01	2.0891100000000000
2009-01-01	2.5167300000000000
2010-01-01	3.2220400000000002
2011-01-01	4.8260200000000000
2012-01-01	6.2122199999999990
2013-01-01	6.8467899999999995
2014-01-01	8.4165100000000000
2015-01-01	8.9794100000000010
2016-01-01	8.7253500000000000