| Year | Count |
|---|---|
| 1948 | 5 |
| 1953 | 5 |
| 1954 | 11 |
| 1955 | 12 |
| 1956 | 13 |
| 1957 | 32 |
| 1958 | 46 |
| 1959 | 26 |
| 1960 | 64 |
| 1961 | 40 |
| 1963 | 36 |
| 1964 | 35 |
| 1965 | 29 |
| 1966 | 38 |
| 1967 | 42 |
| 1968 | 62 |
| 1969 | 74 |
| 1970 | 100 |
| 1971 | 106 |
| 1972 | 63 |
| 1973 | 84 |
| 1974 | 99 |
| 1975 | 94 |
| 1976 | 95 |
| 1977 | 130 |
| 1978 | 144 |
| 1979 | 116 |
| 1980 | 104 |
| 1981 | 48 |
| 1982 | 29 |
| 1983 | 27 |
| 1984 | 43 |
| 1985 | 42 |
| 1986 | 34 |
| 1987 | 27 |
| 1988 | 34 |
| 1989 | 24 |
| 1990 | 37 |
| 1991 | 14 |
| 1992 | 26 |
| 1993 | 26 |
| 1994 | 20 |
| 1995 | 12 |
| 1996 | 7 |
| 1997 | 7 |
| 1998 | 7 |
| 1999 | 9 |
| 2000 | 5 |
| 2002 | 7 |
| 2008 | 5 |