Year	Percent
1999-01-01	2.500
2000-01-01	3.000
2001-01-01	1.800
2002-01-01	2.100
2003-01-01	2.500
2004-01-01	3.100
2005-01-01	3.700
2006-01-01	2.800
2007-01-01	2.600
2008-01-01	2.500
2009-01-01	3.000
2010-01-01	3.525
2011-01-01	3.425
2012-01-01	3.350
2013-01-01	3.350
2014-01-01	3.425
2015-01-01	4.450
2016-01-01	4.300
2017-01-01	4.225