Year	Percent
2000-01-01	28.400
2001-01-01	27.350
2002-01-01	26.150
2003-01-01	26.900
2004-01-01	26.200
2005-01-01	27.200
2006-01-01	28.050
2007-01-01	29.650
2008-01-01	31.575
2009-01-01	32.325
2010-01-01	34.050
2011-01-01	36.875
2012-01-01	38.650
2013-01-01	40.550
2014-01-01	42.450
2015-01-01	44.325
2016-01-01	46.150
2017-01-01	48.275