Year Years 1990 77.6 1991 77.9 1992 78.3 1993 78.6 1994 78.8 1995 79 1996 79.2 1997 79.3 1998 79.4 1999 79.5 2000 79.7 2001 79.9 2002 80.2 2003 80.4 2004 80.6 2005 80.9 2006 81.1 2007 81.2 2008 81.4 2009 81.6 2010 81.8 2011 82 2012 82.1 2013 82.1