Year	Percent
1999-01-01	28.31
2000-01-01	31.68
2001-01-01	32.28
2002-01-01	28.35
2003-01-01	29.91
2004-01-01	31.80
2005-01-01	35.35
2006-01-01	37.72
2007-01-01	35.74
2008-01-01	25.25
2009-01-01	27.65
2010-01-01	26.34
2011-01-01	22.01
2012-01-01	22.50
2013-01-01	26.70
2014-01-01	31.21
2015-01-01	36.10
2016-01-01	35.49
