Year Years 1990 71.9 1991 72.2 1992 72.5 1993 72.8 1994 73.1 1995 73.4 1996 73.8 1997 74.1 1998 74.5 1999 74.8 2000 75 2001 75.2 2002 75.4 2003 75.6 2004 75.8 2005 76 2006 76.2 2007 76.3 2008 76.5 2009 76.6 2010 76.8 2011 76.9 2012 77 2013 77.1