Year Percent 1996-01-01 111.07 1997-01-01 139.06 1998-01-01 158.07 1999-01-01 167.28 2000-01-01 178.03 2001-01-01 183.50 2002-01-01 174.76 2003-01-01 186.68 2004-01-01 186.68 2005-01-01 186.68 2006-01-01 186.68 2007-01-01 186.68 2008-01-01 178.58