| Year | Count |
|---|---|
| 1954 | 5 |
| 1958 | 6 |
| 1962 | 10 |
| 1966 | 5 |
| 1967 | 11 |
| 1968 | 11 |
| 1970 | 47 |
| 1971 | 39 |
| 1972 | 50 |
| 1973 | 75 |
| 1974 | 54 |
| 1975 | 83 |
| 1976 | 71 |
| 1977 | 84 |
| 1978 | 95 |
| 1979 | 171 |
| 1980 | 140 |
| 1981 | 116 |
| 1982 | 89 |
| 1983 | 139 |
| 1984 | 115 |
| 1985 | 124 |
| 1986 | 109 |
| 1987 | 99 |
| 1988 | 65 |
| 1989 | 75 |
| 1990 | 63 |
| 1991 | 40 |
| 1992 | 50 |
| 1993 | 44 |
| 1994 | 19 |
| 1995 | 34 |
| 1996 | 24 |
| 1997 | 15 |
| 1998 | 10 |
| 1999 | 6 |
| 2000 | 15 |
| 2004 | 5 |
| 2007 | 10 |
| 2014 | 6 |
| 2016 | 7 |