Year Measure 1995 4.29 1996 5.02 1997 4.29 1998 4.2 1999 3.8 2000 4 2001 4.2 2002 4.5 2003 4.3 2004 4.5 2005 5 2006 5.1 2007 5.1 2008 5.6 2009 5.5 2010 5.4 2011 5.35639