Year Years 1990 73.1 1991 73.2 1992 73.2 1993 73.3 1994 73.3 1995 73.4 1996 73.5 1997 73.6 1998 73.8 1999 74 2000 74.3 2001 74.5 2002 74.5 2003 74.6 2004 74.9 2005 75 2006 75.1 2007 75.2 2008 75.3 2009 75.3 2010 75.4 2011 75.5 2012 75.5 2013 75.6