Year	Percent
1999-01-01	44.675
2000-01-01	44.200
2001-01-01	43.950
2002-01-01	44.100
2003-01-01	45.175
2004-01-01	42.650
2005-01-01	41.825
2006-01-01	41.275
2007-01-01	41.175
2008-01-01	40.600
2009-01-01	40.300
2010-01-01	40.625
2011-01-01	41.500
2012-01-01	41.200
2013-01-01	41.650
2014-01-01	40.925
2015-01-01	41.075
2016-01-01	40.750
2017-01-01	38.575