Year	Percent
1999-01-01	4.58090526892065
2000-01-01	4.58938433065722
2001-01-01	4.27915534463142
2002-01-01	3.91021069584256
2003-01-01	4.28189768389153
2004-01-01	4.28794123196674
2005-01-01	4.26270207689154
2006-01-01	3.85410254710738
2007-01-01	2.89797043195373
2008-01-01	2.39339735197804
2009-01-01	3.30870285890199
2010-01-01	3.59892778243762
2011-01-01	3.36056761299884
2012-01-01	3.52717775685181
2013-01-01	3.61715342079573