Year	Percent
1997-01-01	91.40700000000001
1998-01-01	71.62820000000000
1999-01-01	59.61780000000000
2000-01-01	69.82500000000000
2001-01-01	74.42190000000000
2002-01-01	67.62700000000000
2003-01-01	71.50880000000000
2004-01-01	75.27240000000000
2005-01-01	71.25290000000000
2006-01-01	73.61570000000000
2007-01-01	69.65120000000000
2008-01-01	74.19810000000000
2009-01-01	71.98280000000000
2010-01-01	64.20200000000000
2011-01-01	62.12430000000000
2012-01-01	58.41210000000000
2013-01-01	56.17340000000000
2014-01-01	56.38080000000000
2015-01-01	57.30290000000000
2016-01-01	52.86930000000000