Year	Percent
1991-01-01	62.1110000610352
1992-01-01	62.1969985961914
1993-01-01	62.4179992675781
1994-01-01	62.6430015563965
1995-01-01	62.9319992065430
1996-01-01	63.0079994201660
1997-01-01	63.1959991455078
1998-01-01	63.4410018920898
1999-01-01	63.7560005187988
2000-01-01	64.1559982299805
2001-01-01	63.8580017089844
2002-01-01	63.5639991760254
2003-01-01	63.4389991760254
2004-01-01	63.4729995727539
2005-01-01	63.5709991455078
2006-01-01	63.3380012512207
2007-01-01	63.2439994812012
2008-01-01	63.2239990234375
2009-01-01	63.2910003662109
2010-01-01	63.3849983215332
2011-01-01	63.5839996337891
2012-01-01	63.7639999389648
2013-01-01	63.9000015258789
2014-01-01	63.2089996337891
2015-01-01	62.9570007324219
2016-01-01	62.5289993286133
2017-01-01	62.3409996032715