Year Years 1990 47 1991 47.5 1992 48 1993 48.6 1994 49.2 1995 49.9 1996 50.7 1997 51.3 1998 51.9 1999 52.4 2000 53 2001 53.7 2002 54.5 2003 55.4 2004 56.3 2005 57.3 2006 58.3 2007 59.1 2008 59.7 2009 60.3 2010 60.7 2011 61 2012 61.3 2013 61.6