| Year | Count |
|---|---|
| 1954 | 5 |
| 1957 | 10 |
| 1958 | 14 |
| 1959 | 18 |
| 1960 | 60 |
| 1961 | 62 |
| 1963 | 52 |
| 1964 | 58 |
| 1965 | 76 |
| 1966 | 96 |
| 1967 | 108 |
| 1968 | 100 |
| 1969 | 137 |
| 1970 | 166 |
| 1971 | 115 |
| 1972 | 79 |
| 1973 | 93 |
| 1974 | 81 |
| 1975 | 76 |
| 1976 | 55 |
| 1977 | 92 |
| 1978 | 94 |
| 1979 | 84 |
| 1980 | 90 |
| 1981 | 41 |
| 1982 | 27 |
| 1983 | 33 |
| 1984 | 36 |
| 1985 | 28 |
| 1986 | 36 |
| 1987 | 38 |
| 1988 | 23 |
| 1989 | 23 |
| 1990 | 27 |
| 1991 | 8 |
| 1992 | 14 |
| 1993 | 10 |
| 1994 | 8 |
| 1995 | 6 |
| 1998 | 5 |
| 1999 | 7 |
| 2000 | 5 |