Year	Percent
1999-01-01	43.525
2000-01-01	44.500
2001-01-01	44.100
2002-01-01	44.550
2003-01-01	44.950
2004-01-01	45.775
2005-01-01	46.850
2006-01-01	47.275
2007-01-01	48.600
2008-01-01	49.500
2009-01-01	49.375
2010-01-01	49.925
2011-01-01	50.000
2012-01-01	50.000
2013-01-01	50.225
2014-01-01	50.800
2015-01-01	50.775
2016-01-01	50.575
2017-01-01	51.000