Year	Percent
1999-01-01	35.350
2000-01-01	37.500
2001-01-01	36.325
2002-01-01	37.450
2003-01-01	38.875
2004-01-01	40.350
2005-01-01	43.400
2006-01-01	42.700
2007-01-01	44.475
2008-01-01	44.450
2009-01-01	45.150
2010-01-01	47.575
2011-01-01	47.825
2012-01-01	47.900
2013-01-01	50.500
2014-01-01	51.275
2015-01-01	52.175
2016-01-01	53.600
2017-01-01	56.875