Year	Percent
1999-01-01	46.5632867018069
2000-01-01	46.7386610350678
2001-01-01	46.9175652013115
2002-01-01	47.0347157147417
2003-01-01	47.4306523976968
2004-01-01	46.5357563396293
2005-01-01	47.1642961536118
2006-01-01	48.1691139503560
2007-01-01	49.1758917498431
2008-01-01	49.7561678652592
2009-01-01	49.4940751049264
2010-01-01	49.5957833790606
2011-01-01	49.9824982386926
2012-01-01	50.2294802909612
2013-01-01	49.9778400744672