Year Total 1971 6378 1972 6195 1973 6760 1974 7643 1975 8413 1976 7809 1977 8151 1978 8705 1979 9033 1980 9272 1981 9729 1982 10010 1983 11310 1984 12680 1985 14600 1986 18400 1987 21390 1988 21450 1989 21880 1990 22620 1991 22200 1992 20390 1993 20060 1994 19270 1995 21150 1996 22490 1997 23730 1998 27080 1999 30640 2000 34380 2001 34880 2002 34840 2003 37940 2004 38270 2005 42930 2006 43730 2007 42600 2008 44730 2009 44310 2010 44620