Year	Percent
1999-01-01	2.700
2000-01-01	2.300
2001-01-01	2.100
2002-01-01	2.700
2003-01-01	3.700
2004-01-01	4.000
2005-01-01	3.800
2006-01-01	3.500
2007-01-01	3.200
2008-01-01	2.900
2009-01-01	3.700
2010-01-01	4.525
2011-01-01	4.075
2012-01-01	4.125
2013-01-01	4.450
2014-01-01	4.650
2015-01-01	4.350
2016-01-01	4.725
2017-01-01	4.625