Year	Percent
1997-01-01	6.4516100000000000
1998-01-01	6.4516100000000000
1999-01-01	6.4516100000000000
2000-01-01	6.4516100000000000
2001-01-01	11.1742000000000000
2002-01-01	8.1540200000000000
2003-01-01	7.9961000000000000
2004-01-01	7.4501100000000005
2005-01-01	8.1511700000000000
2006-01-01	6.6838000000000000
2007-01-01	7.8651700000000000
2008-01-01	7.5369300000000000
2009-01-01	5.0457000000000000
2010-01-01	6.0524500000000000
2011-01-01	9.5936000000000000
2012-01-01	7.5608500000000000
2013-01-01	7.5838600000000005
2014-01-01	7.3563199999999990
2015-01-01	7.1942100000000010
2016-01-01	5.6364900000000000