Year	Percent
1999-01-01	41.075
2000-01-01	40.950
2001-01-01	43.150
2002-01-01	46.275
2003-01-01	48.100
2004-01-01	51.900
2005-01-01	55.075
2006-01-01	55.225
2007-01-01	56.950
2008-01-01	59.850
2009-01-01	58.675
2010-01-01	59.725
2011-01-01	58.775
2012-01-01	60.250
2013-01-01	59.550
2014-01-01	58.850
2015-01-01	58.375
2016-01-01	60.125
2017-01-01	60.000