Year	Percent
2000-01-01	22.8451840900205
2001-01-01	22.7997337106277
2002-01-01	22.0542044229744
2003-01-01	21.8754734729812
2004-01-01	21.5193258474871
2005-01-01	21.7374323153292
2006-01-01	22.0746289023249
2007-01-01	22.0908804357599
2008-01-01	22.5592834760674
2009-01-01	23.0339710386069
2010-01-01	22.8416406920946
2011-01-01	22.5411513999186
2012-01-01	22.2678774344886
2013-01-01	22.1800833781289
2014-01-01	21.1459472735640
2015-01-01	21.1190846920333
2016-01-01	21.0728582410711
2017-01-01	20.6825124288705