Year	Percent
1999-01-01	51.700
2000-01-01	47.875
2001-01-01	46.975
2002-01-01	47.350
2003-01-01	46.550
2004-01-01	47.275
2005-01-01	48.550
2006-01-01	48.775
2007-01-01	50.625
2008-01-01	51.350
2009-01-01	50.525
2010-01-01	48.950
2011-01-01	49.825
2012-01-01	50.275
2013-01-01	49.750
2014-01-01	49.875
2015-01-01	48.700
2016-01-01	49.025
2017-01-01	49.000