Year	Percent
1991-01-01	54.2929992675781
1992-01-01	54.1739997863770
1993-01-01	54.1139984130859
1994-01-01	54.1119995117188
1995-01-01	54.0470008850098
1996-01-01	54.0099983215332
1997-01-01	54.0719985961914
1998-01-01	54.1080017089844
1999-01-01	54.2639999389648
2000-01-01	54.3180007934570
2001-01-01	54.4459991455078
2002-01-01	54.5639991760254
2003-01-01	54.7459983825684
2004-01-01	54.9109992980957
2005-01-01	55.0610008239746
2006-01-01	55.8499984741211
2007-01-01	56.7400016784668
2008-01-01	57.5429992675781
2009-01-01	58.2130012512207
2010-01-01	59.3779983520508
2011-01-01	60.5989990234375
2012-01-01	62.8440017700195
2013-01-01	62.8849983215332
2014-01-01	62.8559989929199
2015-01-01	62.7890014648438
2016-01-01	62.4739990234375
2017-01-01	62.0449981689453