Year	Percent
1991-01-01	63.1034889878130
1992-01-01	63.0834277377929
1993-01-01	63.0383634732079
1994-01-01	62.9366046639945
1995-01-01	62.9323196121025
1996-01-01	62.6692184160226
1997-01-01	62.4630068309776
1998-01-01	62.2626629721018
1999-01-01	62.1237695984073
2000-01-01	62.2671393330972
2001-01-01	62.2834958954862
2002-01-01	62.3813673040535
2003-01-01	62.4973488750620
2004-01-01	62.6729527187788
2005-01-01	62.8905475001213
2006-01-01	63.0962665705267
2007-01-01	63.2267140188747
2008-01-01	63.4270434066907
2009-01-01	63.3278078097175
2010-01-01	63.2486239885100
2011-01-01	63.4096890189131
2012-01-01	63.5764881236946
2013-01-01	63.7205110695842
2014-01-01	63.6137267099129
2015-01-01	63.6318934203749
2016-01-01	63.2717741235598
2017-01-01	63.2954185956724