Year	Percent
1996-12-31	5.9195
1997-12-31	6.6907
1998-12-31	7.1066
1999-12-31	5.1588
2000-12-31	5.7997
2001-12-31	4.9425
2002-12-31	3.8428
2003-12-31	3.5613
2004-12-31	4.3406
2005-12-31	4.6117
2006-12-31	4.6428
2007-12-31	5.5456
2008-12-31	4.6292
2009-12-31	0.5997
2010-12-31	0.5184
2011-12-31	0.5167
2012-12-31	0.4531
2013-12-31	0.4439
2014-12-31	0.4501
2015-12-31	0.5059
2016-12-31	0.417
2017-12-31	0.275