Year	Percent
1991-01-01	62.1619987487793
1992-01-01	61.8810005187988
1993-01-01	62.2760009765625
1994-01-01	62.7330017089844
1995-01-01	62.8750000000000
1996-01-01	62.7639999389648
1997-01-01	63.5180015563965
1998-01-01	62.6360015869141
1999-01-01	61.5750007629395
2000-01-01	62.3019981384277
2001-01-01	62.2449989318848
2002-01-01	60.1769981384277
2003-01-01	59.9970016479492
2004-01-01	60.0239982604980
2005-01-01	60.6049995422363
2006-01-01	61.8849983215332
2007-01-01	62.8540000915527
2008-01-01	63.7779998779297
2009-01-01	63.5579986572266
2010-01-01	64.8020019531250
2011-01-01	65.0660018920898
2012-01-01	65.6259994506836
2013-01-01	65.6380004882813
2014-01-01	66.3030014038086
2015-01-01	67.7350006103516
2016-01-01	67.4290008544922
2017-01-01	67.0770034790039