Year	Percent
2003-01-01	4.6
2004-01-01	4.2
2005-01-01	2.3
2006-01-01	3.1
2007-01-01	3.4
2008-01-01	6.6
2009-01-01	10.5
2010-01-01	14
2011-01-01	18.8
2012-01-01	22.5
2013-01-01	23.5
2014-01-01	22.8
2015-01-01	18.2