Year	Percent
1991-01-01	4.3972300000000000
1992-01-01	4.6550100000000000
1993-01-01	3.0137900000000000
1994-01-01	2.9478000000000000
1995-01-01	4.6915500000000000
1996-01-01	4.1421700000000000
1997-01-01	3.9536400000000000
1998-01-01	3.7614400000000003
1999-01-01	3.5157300000000005
2000-01-01	2.9791900000000000
2001-01-01	3.9609300000000003
2002-01-01	3.3818599999999996
2003-01-01	3.4741500000000000
2004-01-01	3.6558400000000000
2005-01-01	4.0202599999999995
2006-01-01	4.2674800000000000
2007-01-01	4.3645900000000000
2008-01-01	4.7763400000000000
2009-01-01	4.6067900000000000
2010-01-01	4.4425900000000000
2011-01-01	4.9561800000000010
2012-01-01	4.6436300000000000
2013-01-01	2.1404600000000000
2014-01-01	2.2732200000000002
2015-01-01	2.4053700000000000