Year	Percent
1999-01-01	39.325
2000-01-01	37.150
2001-01-01	38.725
2002-01-01	35.200
2003-01-01	32.800
2004-01-01	30.925
2005-01-01	30.200
2006-01-01	28.250
2007-01-01	26.700
2008-01-01	24.750
2009-01-01	22.825
2010-01-01	21.250
2011-01-01	20.275
2012-01-01	18.925
2013-01-01	18.200
2014-01-01	18.000
2015-01-01	17.975
2016-01-01	17.675
2017-01-01	18.000