| Year | Count |
|---|---|
| 1964 | 12 |
| 1965 | 5 |
| 1966 | 29 |
| 1967 | 7 |
| 1968 | 33 |
| 1969 | 72 |
| 1970 | 186 |
| 1971 | 423 |
| 1972 | 412 |
| 1973 | 612 |
| 1974 | 725 |
| 1975 | 801 |
| 1976 | 907 |
| 1977 | 1,216 |
| 1978 | 1,270 |
| 1979 | 1,545 |
| 1980 | 1,360 |
| 1981 | 1,171 |
| 1982 | 1,046 |
| 1983 | 813 |
| 1984 | 931 |
| 1985 | 994 |
| 1986 | 853 |
| 1987 | 759 |
| 1988 | 721 |
| 1989 | 698 |
| 1989 | 7 |
| 1990 | 592 |
| 1991 | 691 |
| 1992 | 569 |
| 1993 | 481 |
| 1994 | 406 |
| 1995 | 224 |
| 1996 | 138 |
| 1997 | 142 |
| 1998 | 74 |
| 1999 | 27 |
| 2000 | 7 |
| 2001 | 5 |
| 2003 | 7 |
| 2004 | 10 |