Year	Percent
1999-01-01	49.950
2000-01-01	48.000
2001-01-01	49.150
2002-01-01	46.200
2003-01-01	44.225
2004-01-01	42.625
2005-01-01	41.125
2006-01-01	39.325
2007-01-01	38.100
2008-01-01	36.425
2009-01-01	34.900
2010-01-01	33.775
2011-01-01	32.675
2012-01-01	31.625
2013-01-01	31.250
2014-01-01	31.200
2015-01-01	30.950
2016-01-01	30.800
2017-01-01	31.175