Year	Percent
1991-01-01	11.4110002517700
1992-01-01	11.3819999694824
1993-01-01	11.4049997329712
1994-01-01	11.5369997024536
1995-01-01	11.4589996337891
1996-01-01	11.3219995498657
1997-01-01	11.5039997100830
1998-01-01	11.4540004730225
1999-01-01	11.4540004730225
2000-01-01	11.3859996795654
2001-01-01	11.4119997024536
2002-01-01	11.4099998474121
2003-01-01	11.3269996643066
2004-01-01	11.4409999847412
2005-01-01	11.4390001296997
2006-01-01	11.4670000076294
2007-01-01	11.4650001525879
2008-01-01	11.4320001602173
2009-01-01	11.4270000457764
2010-01-01	11.4440002441406
2011-01-01	11.4449996948242
2012-01-01	11.4540004730225
2013-01-01	11.2700004577637
2014-01-01	11.4130001068115
2015-01-01	11.4589996337891
2016-01-01	11.0290002822876
2017-01-01	10.6120004653931