| Year | Count |
|---|---|
| 1956 | 5 |
| 1960 | 15 |
| 1962 | 16 |
| 1963 | 12 |
| 1966 | 10 |
| 1968 | 21 |
| 1969 | 22 |
| 1970 | 24 |
| 1971 | 51 |
| 1972 | 3,726 |
| 1973 | 3,150 |
| 1974 | 962 |
| 1975 | 676 |
| 1976 | 466 |
| 1977 | 382 |
| 1978 | 326 |
| 1979 | 307 |
| 1980 | 216 |
| 1981 | 109 |
| 1982 | 152 |
| 1983 | 102 |
| 1984 | 111 |
| 1985 | 130 |
| 1986 | 92 |
| 1987 | 59 |
| 1988 | 62 |
| 1989 | 78 |
| 1990 | 64 |
| 1991 | 42 |
| 1992 | 38 |
| 1993 | 16 |
| 1994 | 19 |
| 1995 | 27 |
| 1996 | 6 |
| 1997 | 6 |
| 1998 | 5 |
| 2001 | 12 |
| 2009 | 6 |