Year	Percent
2000-01-01	23.650
2001-01-01	22.175
2002-01-01	20.875
2003-01-01	21.950
2004-01-01	21.375
2005-01-01	21.475
2006-01-01	20.250
2007-01-01	20.575
2008-01-01	21.625
2009-01-01	23.125
2010-01-01	25.875
2011-01-01	29.025
2012-01-01	31.275
2013-01-01	33.325
2014-01-01	35.150
2015-01-01	37.325
2016-01-01	39.000
2017-01-01	40.550