| Year | Count |
|---|---|
| 1954 | 30 |
| 1955 | 17 |
| 1956 | 96 |
| 1957 | 137 |
| 1958 | 262 |
| 1959 | 186 |
| 1960 | 114 |
| 1961 | 153 |
| 1962 | 155 |
| 1963 | 124 |
| 1964 | 218 |
| 1965 | 269 |
| 1966 | 302 |
| 1967 | 375 |
| 1968 | 550 |
| 1969 | 707 |
| 1970 | 781 |
| 1971 | 808 |
| 1972 | 760 |
| 1973 | 778 |
| 1974 | 822 |
| 1975 | 909 |
| 1976 | 831 |
| 1977 | 795 |
| 1978 | 745 |
| 1979 | 647 |
| 1980 | 659 |
| 1981 | 577 |
| 1982 | 460 |
| 1983 | 508 |
| 1984 | 471 |
| 1985 | 496 |
| 1986 | 447 |
| 1987 | 429 |
| 1988 | 375 |
| 1989 | 309 |
| 1990 | 288 |
| 1991 | 226 |
| 1992 | 171 |
| 1993 | 163 |
| 1994 | 93 |
| 1995 | 83 |
| 1996 | 49 |
| 1997 | 28 |
| 1998 | 32 |
| 1999 | 24 |
| 2000 | 17 |
| 2001 | 17 |
| 2002 | 5 |