Year	Percent
1999-01-01	44.975
2000-01-01	43.150
2001-01-01	39.225
2002-01-01	35.975
2003-01-01	34.550
2004-01-01	31.425
2005-01-01	30.325
2006-01-01	30.225
2007-01-01	29.550
2008-01-01	28.700
2009-01-01	27.750
2010-01-01	27.550
2011-01-01	27.025
2012-01-01	27.900
2013-01-01	30.975
2014-01-01	33.025
2015-01-01	34.400
2016-01-01	36.150
2017-01-01	36.475