Year	Percent
1999-01-01	24.575
2000-01-01	24.325
2001-01-01	25.475
2002-01-01	26.925
2003-01-01	28.475
2004-01-01	31.675
2005-01-01	35.000
2006-01-01	36.675
2007-01-01	38.800
2008-01-01	41.900
2009-01-01	42.825
2010-01-01	45.075
2011-01-01	45.950
2012-01-01	48.500
2013-01-01	49.475
2014-01-01	50.075
2015-01-01	51.800
2016-01-01	53.875
2017-01-01	56.350