Year	Percent
1999-01-01	30.525
2000-01-01	30.125
2001-01-01	29.550
2002-01-01	30.150
2003-01-01	30.000
2004-01-01	30.300
2005-01-01	31.050
2006-01-01	31.350
2007-01-01	31.700
2008-01-01	31.175
2009-01-01	31.575
2010-01-01	31.325
2011-01-01	31.300
2012-01-01	30.575
2013-01-01	30.150
2014-01-01	29.725
2015-01-01	29.075
2016-01-01	28.125
2017-01-01	27.900