Year Total 1971 342.3 1972 339.1 1973 342.4 1974 366.4 1975 380 1976 404.9 1977 441.8 1978 486.9 1979 499 1980 527.3 1981 568.4 1982 568.1 1983 539.4 1984 593.9 1985 604 1986 605.1 1987 599.6 1988 610 1989 612.4 1990 612.3 1991 602.6 1992 623.6 1993 662.6 1994 650.9 1995 604.2 1996 701.3 1997 704 1998 643.1 1999 730.3 2000 755.5 2001 678 2002 737.7 2003 688.6 2004 752.6 2005 735.4 2006 750.8 2007 695.2 2008 697.9 2009 666.2