Year	Percent
1997-12-31	7.335
1998-12-31	5.225
1999-12-31	6.255
2000-12-31	5.525
2001-12-31	4.2
2002-12-31	3.795
2003-12-31	4.245
2004-12-31	4.755
2005-12-31	4.395
2006-12-31	5.41
2007-12-31	5.135
2008-12-31	1.175
2009-12-31	0.785
2010-12-31	0.705
2011-12-31	0.495
2012-12-31	0.425