Year Measure 1995 6.72 1996 7.05 1997 6.57 1998 5.8 1999 6 2000 6.4 2001 7.1 2002 7.1 2003 7 2004 6.9 2005 7.3 2006 7.6 2007 7.5 2008 7.3 2009 7.7 2010 7.8 2011 8.0409