Year	Percent
1999-01-01	47.225
2000-01-01	47.900
2001-01-01	48.125
2002-01-01	47.650
2003-01-01	46.500
2004-01-01	48.875
2005-01-01	49.175
2006-01-01	49.425
2007-01-01	50.200
2008-01-01	50.975
2009-01-01	50.500
2010-01-01	49.500
2011-01-01	48.050
2012-01-01	47.350
2013-01-01	45.950
2014-01-01	46.700
2015-01-01	46.700
2016-01-01	47.550
2017-01-01	49.750