Year	Percent
1999-01-01	37.350
2000-01-01	37.025
2001-01-01	36.750
2002-01-01	37.025
2003-01-01	37.875
2004-01-01	35.025
2005-01-01	33.900
2006-01-01	33.250
2007-01-01	33.425
2008-01-01	32.475
2009-01-01	32.150
2010-01-01	32.625
2011-01-01	33.550
2012-01-01	33.100
2013-01-01	33.400
2014-01-01	32.750
2015-01-01	32.050
2016-01-01	31.400
2017-01-01	28.775