Year	Percent
1997-01-01	43.73693000
1998-01-01	82.10876083
1999-01-01	86.86690140
2000-01-01	85.19781494
2001-01-01	86.12152100
2002-01-01	85.77000046
2003-01-01	85.69528198
2004-01-01	85.89543915
2005-01-01	85.24261093
2006-01-01	87.92010498
2007-01-01	87.71249008
2008-01-01	87.59649658
2009-01-01	86.66477966
2010-01-01	84.42794037
2011-01-01	84.33531952
2012-01-01	83.18633270
2013-01-01	84.30039215