Year	Percent
2000-01-01	3.19912785129351
2001-01-01	3.44607082191054
2002-01-01	3.59581887714810
2003-01-01	3.71029743504206
2004-01-01	3.74868044416494
2005-01-01	4.19046862641551
2006-01-01	3.34380985162672
2007-01-01	2.42323383890816
2008-01-01	2.36151518054677
2009-01-01	2.60359537168929
2010-01-01	2.93958386119730
2011-01-01	2.98904497861000
2012-01-01	2.63419792175550
2013-01-01	3.23198460536990
2014-01-01	3.23646089522149
2015-01-01	3.99969039473122
2016-01-01	3.90975995877720
2017-01-01	3.68948621908922