\f1990 72.1 1991 73 1992 70.7 1993 72.1 1994 72.7 1995 71.2 1996 71.8 1997 72.3 1998 72.9 1999 71.8 2000 72.9 2001 73.6 2002 73.6 2003 72.9 2004 74.1 2005 74.1 2006 73.6 2007 72.9 2008 71.8 2009 73.2 2010 77.7