Year	Percent
2000-01-01	31.225
2001-01-01	30.825
2002-01-01	30.375
2003-01-01	31.150
2004-01-01	31.400
2005-01-01	31.500
2006-01-01	31.725
2007-01-01	30.600
2008-01-01	29.400
2009-01-01	30.250
2010-01-01	31.325
2011-01-01	31.375
2012-01-01	31.550
2013-01-01	31.675
2014-01-01	31.825
2015-01-01	31.825
2016-01-01	32.350
2017-01-01	32.975