Year Total 1960 995 1961 932.3 1962 919 1963 903.8 1964 805.4 1965 784.7 1966 739.7 1967 538.4 1968 328.6 1969 186.8 1970 377.7 1971 329.2 1972 434.1 1973 426.2 1974 447.4 1975 526.4 1976 596.2 1977 912.5 1978 877 1979 972 1980 952.4 1981 1563 1982 2577 1983 3099 1984 3534 1985 4979 1986 6508 1987 8156 1988 8308 1989 9532 1990 10080 1991 11920 1992 12920 1993 13890 1994 15090 1995 15590 1996 17670 1997 20240 1998 20390 1999 23780 2000 27730 2001 27140 2002 28590 2003 28470 2004 31110 2005 31300 2006 29550 2007 27080 2008 26620 2009 23910 2010 23210