Year	Percent
1999-01-01	49.025
2000-01-01	49.725
2001-01-01	49.775
2002-01-01	49.850
2003-01-01	50.900
2004-01-01	50.700
2005-01-01	50.975
2006-01-01	51.050
2007-01-01	50.675
2008-01-01	50.325
2009-01-01	49.600
2010-01-01	50.225
2011-01-01	50.350
2012-01-01	51.850
2013-01-01	52.600
2014-01-01	55.900
2015-01-01	57.775
2016-01-01	60.225
2017-01-01	61.275