Year	Percent
2000-01-01	92.2022639620182
2001-01-01	91.7828427585012
2002-01-01	91.8882848834584
2003-01-01	92.0190181417520
2004-01-01	91.7113685350830
2005-01-01	91.2887295280214
2006-01-01	90.8500458843049
2007-01-01	90.4928547865081
2008-01-01	90.4082588442914
2009-01-01	89.9320407406009
2010-01-01	90.2234655720884
2011-01-01	90.4870291270331
2012-01-01	90.7041896599508
2013-01-01	90.7551263747435
2014-01-01	91.4014137524315
2015-01-01	91.1503402974698
2016-01-01	91.1540613484248
2017-01-01	90.9949260008536