Year Years 1990 58.5 1991 59.1 1992 59.8 1993 60.3 1994 61.1 1995 61.7 1996 62.4 1997 63.1 1998 63.7 1999 64.3 2000 64.9 2001 65.5 2002 65.7 2003 66.4 2004 66.8 2005 67.3 2006 67.8 2007 68.2 2008 68.6 2009 69 2010 69.5 2011 69.9 2012 70.3 2013 70.6