Year	Percent
1999-01-01	35.700
2000-01-01	35.800
2001-01-01	35.150
2002-01-01	35.875
2003-01-01	36.550
2004-01-01	34.150
2005-01-01	34.025
2006-01-01	34.350
2007-01-01	33.625
2008-01-01	34.375
2009-01-01	34.550
2010-01-01	34.750
2011-01-01	36.300
2012-01-01	36.975
2013-01-01	36.925
2014-01-01	36.700
2015-01-01	37.075
2016-01-01	38.675
2017-01-01	36.825