Year	Percent
1999-01-01	43.500
2000-01-01	45.200
2001-01-01	44.200
2002-01-01	46.975
2003-01-01	48.850
2004-01-01	50.400
2005-01-01	51.825
2006-01-01	53.625
2007-01-01	54.975
2008-01-01	56.550
2009-01-01	57.950
2010-01-01	58.950
2011-01-01	59.850
2012-01-01	60.625
2013-01-01	60.650
2014-01-01	60.275
2015-01-01	60.325
2016-01-01	60.300
2017-01-01	59.775