Year	Percent
1998-01-01	71.75780000000000
1999-01-01	59.12830000000000
2000-01-01	66.40000000000000
2001-01-01	73.40000000000000
2002-01-01	73.87560000000000
2003-01-01	75.74620000000000
2004-01-01	76.32600000000001
2005-01-01	75.89450000000000
2006-01-01	76.64480000000000
2007-01-01	75.76880000000000
2008-01-01	71.10810000000000
2009-01-01	75.16760000000000
2010-01-01	76.27190000000000
2011-01-01	59.89530000000000
2012-01-01	74.58960000000000
2013-01-01	72.18900000000000
2014-01-01	72.61840000000000
2015-01-01	71.94880000000000
2016-01-01	68.46080000000000