Year Years 1990 57.1 1991 57.5 1992 57.9 1993 58.2 1994 58.4 1995 58.5 1996 58.6 1997 58.7 1998 58.8 1999 59 2000 59.2 2001 59.4 2002 59.8 2003 60.3 2004 60.9 2005 61.4 2006 62.1 2007 62.7 2008 63.2 2009 63.6 2010 64 2011 64.3 2012 64.6 2013 64.9