Year Annual Number 1970 0 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 54 1978 105000 1979 0 1980 0 1981 0 1982 0 1983 0 1984 350100 1985 0 1986 0 1987 0 1988 4100 1989 0 1990 0 1991 0 1992 0 1993 0 1994 2502000 1995 0 1996 200000 1997 0 1998 0 1999 0 2000 1436 2001 0 2002 4020 2003 23020 2004 0 2005 0 2006 0 2007 162800 2008 220000