Year	Percent
1999-01-01	38.525
2000-01-01	38.475
2001-01-01	39.075
2002-01-01	39.150
2003-01-01	39.475
2004-01-01	38.875
2005-01-01	38.625
2006-01-01	39.150
2007-01-01	38.925
2008-01-01	39.150
2009-01-01	39.625
2010-01-01	39.225
2011-01-01	40.300
2012-01-01	40.250
2013-01-01	40.325
2014-01-01	40.750
2015-01-01	41.100
2016-01-01	41.275
2017-01-01	40.850