Year	Percent
1999-01-01	43.700
2000-01-01	42.425
2001-01-01	43.100
2002-01-01	41.175
2003-01-01	39.750
2004-01-01	38.750
2005-01-01	37.575
2006-01-01	36.425
2007-01-01	35.550
2008-01-01	34.600
2009-01-01	34.300
2010-01-01	33.950
2011-01-01	33.725
2012-01-01	33.500
2013-01-01	33.850
2014-01-01	34.400
2015-01-01	34.450
2016-01-01	34.650
2017-01-01	35.100