Year	Percent
2001-01-01	6.99
2002-01-01	8.65
2003-01-01	8.72
2004-01-01	9.40
2005-01-01	10.52
2006-01-01	11.63
2007-01-01	12.94
2008-01-01	12.10
2009-01-01	14.08
2010-01-01	14.99
2011-01-01	15.43
2012-01-01	16.88
2013-01-01	17.05
2014-01-01	17.51
2015-01-01	17.07
2016-01-01	17.12