Year	Percent
1999-01-01	32.950
2000-01-01	29.825
2001-01-01	28.850
2002-01-01	28.700
2003-01-01	29.275
2004-01-01	27.975
2005-01-01	28.125
2006-01-01	29.150
2007-01-01	30.925
2008-01-01	30.825
2009-01-01	26.825
2010-01-01	23.800
2011-01-01	24.825
2012-01-01	24.100
2013-01-01	24.425
2014-01-01	26.850
2015-01-01	28.375
2016-01-01	31.875
2017-01-01	32.400