Year	Percent
1999-01-01	38.450
2000-01-01	41.300
2001-01-01	43.125
2002-01-01	45.050
2003-01-01	46.925
2004-01-01	48.825
2005-01-01	51.775
2006-01-01	53.750
2007-01-01	55.225
2008-01-01	55.375
2009-01-01	53.250
2010-01-01	52.800
2011-01-01	52.575
2012-01-01	51.150
2013-01-01	50.300
2014-01-01	51.225
2015-01-01	52.675
2016-01-01	54.300
2017-01-01	55.650