Year	Percent
1999-01-01	3.100
2000-01-01	2.700
2001-01-01	2.500
2002-01-01	2.900
2003-01-01	4.100
2004-01-01	4.300
2005-01-01	4.500
2006-01-01	4.000
2007-01-01	3.700
2008-01-01	3.400
2009-01-01	4.100
2010-01-01	4.850
2011-01-01	4.400
2012-01-01	4.525
2013-01-01	4.800
2014-01-01	4.850
2015-01-01	4.850
2016-01-01	4.950
2017-01-01	4.825