Year	Percent
1999-01-01	2.200
2000-01-01	1.600
2001-01-01	1.000
2002-01-01	2.200
2003-01-01	3.300
2004-01-01	3.500
2005-01-01	3.200
2006-01-01	2.700
2007-01-01	2.300
2008-01-01	2.200
2009-01-01	3.300
2010-01-01	4.225
2011-01-01	3.725
2012-01-01	3.825
2013-01-01	4.300
2014-01-01	4.450
2015-01-01	4.100
2016-01-01	4.525
2017-01-01	4.225