Year	Percent
1998-01-01	47.9269272337490
1999-01-01	48.4978697577408
2000-01-01	49.3685939996367
2001-01-01	49.8646026409649
2002-01-01	49.3949567344081
2003-01-01	48.7306412630859
2004-01-01	48.3094239463483
2005-01-01	48.0718320479651
2006-01-01	48.2714973735653
2007-01-01	48.3063022936326
2008-01-01	48.4645489193640
2009-01-01	47.0265272764108
2010-01-01	46.3462896052688
2011-01-01	44.9160985524744
2012-01-01	43.2699716206381
2013-01-01	42.3898633663942
2014-01-01	43.3183363744354