Year	Percent
1999-01-01	39.000
2000-01-01	39.700
2001-01-01	37.675
2002-01-01	39.000
2003-01-01	39.550
2004-01-01	40.000
2005-01-01	43.025
2006-01-01	43.975
2007-01-01	43.375
2008-01-01	43.750
2009-01-01	41.725
2010-01-01	40.250
2011-01-01	39.225
2012-01-01	37.650
2013-01-01	35.900
2014-01-01	34.000
2015-01-01	33.175
2016-01-01	31.275
2017-01-01	31.475