Year	Percent
1996-12-31	5.782
1997-12-31	6.4808
1998-12-31	7.1403
1999-12-31	5.1736
2000-12-31	5.8328
2001-12-31	4.9954
2002-12-31	3.8642
2003-12-31	3.5481
2004-12-31	4.3184
2005-12-31	4.6497
2006-12-31	4.6436
2007-12-31	5.5465
2008-12-31	4.6275
2009-12-31	0.6174
2010-12-31	0.5125
2011-12-31	0.5005
2012-12-31	0.4514
2013-12-31	0.4347
2014-12-31	0.4411
2015-12-31	0.4985
2016-12-31	0.3954
2017-12-31	0.2454