| Year | Count |
|---|---|
| 1963 | 5 |
| 1966 | 6 |
| 1967 | 28 |
| 1968 | 22 |
| 1969 | 32 |
| 1970 | 122 |
| 1971 | 388 |
| 1972 | 359 |
| 1973 | 318 |
| 1974 | 312 |
| 1975 | 247 |
| 1976 | 166 |
| 1977 | 180 |
| 1978 | 151 |
| 1979 | 74 |
| 1980 | 40 |
| 1981 | 35 |
| 1982 | 34 |
| 1983 | 30 |
| 1985 | 10 |
| 1986 | 10 |
| 1987 | 8 |
| 1988 | 22 |
| 1989 | 5 |
| 1990 | 9 |
| 1991 | 7 |
| 1992 | 26 |
| 1993 | 15 |
| 1994 | 11 |
| 1995 | 11 |
| 1996 | 11 |
| 1997 | 6 |
| 1998 | 5 |
| 1999 | 6 |
| 2000 | 7 |
| 2002 | 6 |
| 2003 | 10 |
| 2008 | 5 |
| 2011 | 8 |