| Year | Count |
|---|---|
| 1953 | 6 |
| 1955 | 6 |
| 1956 | 24 |
| 1957 | 8 |
| 1958 | 20 |
| 1959 | 5 |
| 1960 | 17 |
| 1961 | 6 |
| 1962 | 13 |
| 1963 | 18 |
| 1964 | 39 |
| 1965 | 236 |
| 1966 | 220 |
| 1967 | 458 |
| 1968 | 626 |
| 1969 | 816 |
| 1970 | 915 |
| 1971 | 814 |
| 1972 | 550 |
| 1973 | 483 |
| 1974 | 346 |
| 1975 | 361 |
| 1976 | 264 |
| 1977 | 326 |
| 1978 | 200 |
| 1979 | 175 |
| 1980 | 276 |
| 1981 | 236 |
| 1982 | 149 |
| 1983 | 133 |
| 1984 | 116 |
| 1985 | 108 |
| 1986 | 140 |
| 1987 | 61 |
| 1988 | 59 |
| 1989 | 58 |
| 1989 | 5 |
| 1990 | 39 |
| 1991 | 55 |
| 1992 | 41 |
| 1993 | 50 |
| 1994 | 5 |
| 1995 | 21 |
| 1996 | 10 |
| 1997 | 30 |
| 1998 | 26 |
| 1999 | 5 |
| 2000 | 20 |
| 2011 | 18 |
| 2021 | 5 |