| Year | Count |
|---|---|
| 1949 | 6 |
| 1952 | 10 |
| 1955 | 16 |
| 1956 | 7 |
| 1957 | 5 |
| 1959 | 16 |
| 1960 | 67 |
| 1961 | 83 |
| 1962 | 87 |
| 1963 | 70 |
| 1964 | 74 |
| 1965 | 75 |
| 1966 | 63 |
| 1967 | 30 |
| 1968 | 25 |
| 1969 | 11 |
| 1970 | 10 |
| 1971 | 9 |
| 1972 | 6 |
| 1980 | 15 |
| 1981 | 11 |
| 1982 | 5 |
| 1983 | 25 |
| 1984 | 13 |
| 1985 | 29 |
| 1986 | 24 |
| 1987 | 18 |
| 1988 | 22 |
| 1989 | 40 |
| 1990 | 28 |
| 1991 | 17 |
| 1992 | 18 |
| 1993 | 22 |
| 1994 | 20 |
| 1995 | 13 |
| 1997 | 14 |
| 1998 | 5 |
| 2000 | 19 |
| 2006 | 17 |
| 2007 | 5 |
| 2011 | 10 |
| 2015 | 10 |