Year	Percent
1991-01-01	9.59700012207031
1992-01-01	9.46199989318848
1993-01-01	9.47700023651123
1994-01-01	9.56999969482422
1995-01-01	9.62100028991699
1996-01-01	9.75599956512451
1997-01-01	9.72299957275391
1998-01-01	9.89799976348877
1999-01-01	10.02600002288820
2000-01-01	9.84599971771240
2001-01-01	9.98200035095215
2002-01-01	10.17599964141850
2003-01-01	10.19499969482420
2004-01-01	10.11800003051760
2005-01-01	10.06400012969970
2006-01-01	9.76700019836426
2007-01-01	9.62699985504150
2008-01-01	9.40299987792969
2009-01-01	9.34599971771240
2010-01-01	9.27600002288818
2011-01-01	9.19499969482422
2012-01-01	8.79300022125244
2013-01-01	8.84500026702881
2014-01-01	8.94499969482422
2015-01-01	9.04699993133545
2016-01-01	8.66199970245361
2017-01-01	8.45600032806396