Year	Percent
1998-01-01	5.900
1999-01-01	6.000
2000-01-01	6.500
2001-01-01	6.300
2002-01-01	6.800
2003-01-01	6.400
2004-01-01	6.250
2005-01-01	6.250
2006-01-01	6.800
2007-01-01	6.600
2008-01-01	5.900
2009-01-01	6.400
2010-01-01	6.120
2011-01-01	5.590
2012-01-01	6.020
2013-01-01	6.860
2014-01-01	7.235
2015-01-01	7.445