Year	Percent
1998-01-01	84.35160828
1999-01-01	84.29559326
2000-01-01	88.47992706
2001-01-01	86.92575073
2002-01-01	85.65083313
2003-01-01	85.71334839
2004-01-01	96.92250824
2005-01-01	91.08358002
2006-01-01	84.32255173
2007-01-01	84.94747925
2008-01-01	88.16595840
2009-01-01	84.28985596
2010-01-01	93.83166504
2011-01-01	94.56479263
2012-01-01	89.07015228
2013-01-01	89.67045593