Year	Percent
1999-01-01	50.550
2000-01-01	50.225
2001-01-01	50.975
2002-01-01	50.950
2003-01-01	50.250
2004-01-01	50.300
2005-01-01	49.850
2006-01-01	49.350
2007-01-01	49.700
2008-01-01	50.100
2009-01-01	50.150
2010-01-01	49.650
2011-01-01	49.325
2012-01-01	48.325
2013-01-01	47.850
2014-01-01	46.325
2015-01-01	45.250
2016-01-01	44.275
2017-01-01	43.725