| Year | Count |
|---|---|
| 1964 | 6 |
| 1965 | 5 |
| 1968 | 5 |
| 1969 | 17 |
| 1970 | 11 |
| 1971 | 23 |
| 1972 | 44 |
| 1973 | 29 |
| 1974 | 104 |
| 1975 | 857 |
| 1976 | 759 |
| 1977 | 839 |
| 1978 | 787 |
| 1979 | 692 |
| 1980 | 636 |
| 1981 | 619 |
| 1982 | 608 |
| 1983 | 455 |
| 1984 | 358 |
| 1985 | 520 |
| 1986 | 498 |
| 1987 | 413 |
| 1988 | 374 |
| 1989 | 181 |
| 1990 | 210 |
| 1991 | 140 |
| 1992 | 106 |
| 1993 | 19 |
| 1994 | 54 |
| 1995 | 37 |
| 1996 | 58 |
| 1997 | 10 |
| 1998 | 33 |
| 1999 | 5 |
| 2000 | 10 |
| 2001 | 17 |
| 2002 | 10 |
| 2003 | 12 |
| 2004 | 34 |
| 2006 | 5 |
| 2007 | 9 |