Year Years 1990 70.7 1991 71.1 1992 71.4 1993 71.7 1994 72 1995 72.3 1996 72.6 1997 72.9 1998 73.2 1999 73.4 2000 73.7 2001 73.9 2002 74 2003 74.1 2004 74.2 2005 74.3 2006 74.3 2007 74.3 2008 74.6 2009 74.8 2010 75 2011 75.2 2012 75.4 2013 75.5