Year Total 1971 42810 1972 44400 1973 46240 1974 47530 1975 49960 1976 52100 1977 54070 1978 54030 1979 51860 1980 52590 1981 54700 1982 55150 1983 55930 1984 55680 1985 54320 1986 54020 1987 52560 1988 53510 1989 49780 1990 40830 1991 35970 1992 34470 1993 33390 1994 31710 1995 32320 1996 32820 1997 31450 1998 28810 1999 27840 2000 28280 2001 27650 2002 29110 2003 29260 2004 28360 2005 27790 2006 27920 2007 27700 2008 28930 2009 28300