Year	Percent
1999-01-01	28.075
2000-01-01	28.800
2001-01-01	28.425
2002-01-01	28.850
2003-01-01	28.625
2004-01-01	28.400
2005-01-01	28.925
2006-01-01	28.900
2007-01-01	29.025
2008-01-01	28.800
2009-01-01	29.800
2010-01-01	30.925
2011-01-01	31.625
2012-01-01	32.625
2013-01-01	33.750
2014-01-01	33.550
2015-01-01	33.250
2016-01-01	32.225
2017-01-01	33.600