Year	Percent
1999-01-01	54.3697923270312
2000-01-01	54.5053586236252
2001-01-01	54.2132525687985
2002-01-01	53.7101639326072
2003-01-01	53.9996670029631
2004-01-01	52.8808537491592
2005-01-01	53.1919163083194
2006-01-01	54.1800594748176
2007-01-01	55.4240292260818
2008-01-01	55.5345241444632
2009-01-01	54.4703849016359
2010-01-01	54.6053700073337
2011-01-01	55.1243266973120
2012-01-01	55.1019989441779
2013-01-01	54.4919958395776