Year Years 1990 68 1991 68.3 1992 68.6 1993 68.9 1994 69.3 1995 69.6 1996 69.9 1997 70.3 1998 70.7 1999 71.1 2000 71.5 2001 71.9 2002 72.4 2003 72.9 2004 73.4 2005 73.9 2006 74.4 2007 74.9 2008 75.1 2009 75.6 2010 75.9 2011 76.1 2012 76.3 2013 76.5