Year	Percent
1999-01-01	41.275
2000-01-01	39.150
2001-01-01	37.150
2002-01-01	36.600
2003-01-01	35.225
2004-01-01	40.350
2005-01-01	40.525
2006-01-01	40.625
2007-01-01	41.825
2008-01-01	42.875
2009-01-01	40.850
2010-01-01	39.925
2011-01-01	37.400
2012-01-01	34.375
2013-01-01	33.850
2014-01-01	33.600
2015-01-01	35.350
2016-01-01	33.725
2017-01-01	39.150