Year Measure 1995 8.61 1996 8.87 1997 8.92 1998 9 1999 8.9 2000 9.1 2001 8.6 2002 8.5 2003 8.8 2004 8.9 2005 8.9 2006 8.8 2007 8.7 2008 7.9 2009 8.6 2010 8.6 2011 8.98985