Year	Percent
1999-01-01	38.875
2000-01-01	39.650
2001-01-01	39.175
2002-01-01	39.500
2003-01-01	39.800
2004-01-01	40.250
2005-01-01	41.350
2006-01-01	41.550
2007-01-01	42.600
2008-01-01	43.325
2009-01-01	43.150
2010-01-01	43.650
2011-01-01	43.650
2012-01-01	43.625
2013-01-01	43.850
2014-01-01	44.275
2015-01-01	44.275
2016-01-01	44.175
2017-01-01	45.275