Year	Percent
1999-01-01	8.56170923792612
2000-01-01	7.00965041393407
2001-01-01	6.60793134438822
2002-01-01	7.51127666623084
2003-01-01	8.17214430155883
2004-01-01	8.38737744183866
2005-01-01	8.43897494999346
2006-01-01	8.24906414060013
2007-01-01	7.45926367198914
2008-01-01	6.97080803861054
2009-01-01	7.90631389813198
2010-01-01	8.29304772853054
2011-01-01	7.13979459286801
2012-01-01	7.53793157734694
2013-01-01	8.42518511385572
2014-01-01	8.52289002303051
2015-01-01	8.48107025247975
2016-01-01	7.83332887688285
2017-01-01	7.08873550235205