Year Percent 1996-12-31 6.3355 1997-12-31 6.76 1998-12-31 6.9724 1999-12-31 5.1789 2000-12-31 6.0014 2001-12-31 4.7896 2002-12-31 3.9707 2003-12-31 3.5764 2004-12-31 4.5733 2005-12-31 4.5887 2006-12-31 4.7455 2007-12-31 5.6662 2008-12-31 4.4515 2009-12-31 0.6059 2010-12-31 0.5481 2011-12-31 0.6009 2012-12-31 0.4409