Year	Percent
1999-01-01	43.075
2000-01-01	42.875
2001-01-01	43.650
2002-01-01	43.100
2003-01-01	42.900
2004-01-01	42.000
2005-01-01	41.125
2006-01-01	41.125
2007-01-01	40.400
2008-01-01	40.275
2009-01-01	40.400
2010-01-01	39.700
2011-01-01	40.625
2012-01-01	40.525
2013-01-01	40.175
2014-01-01	40.125
2015-01-01	40.350
2016-01-01	40.600
2017-01-01	40.400