Year Years 1990 64.9 1991 65 1992 65.3 1993 65.4 1994 65.2 1995 64.8 1996 64.6 1997 64.4 1998 64.4 1999 64.5 2000 64.4 2001 64.2 2002 63.7 2003 63 2004 62.6 2005 62.6 2006 63 2007 63.1 2008 63 2009 63.1 2010 63.3 2011 63.5 2012 63.8 2013 64