| Year | Count |
|---|---|
| 1958 | 28 |
| 1959 | 51 |
| 1960 | 120 |
| 1961 | 206 |
| 1962 | 150 |
| 1963 | 194 |
| 1964 | 124 |
| 1965 | 126 |
| 1966 | 132 |
| 1967 | 125 |
| 1968 | 119 |
| 1969 | 153 |
| 1970 | 116 |
| 1971 | 99 |
| 1972 | 73 |
| 1973 | 62 |
| 1974 | 62 |
| 1975 | 41 |
| 1976 | 45 |
| 1977 | 42 |
| 1978 | 26 |
| 1979 | 28 |
| 1980 | 12 |
| 1981 | 20 |
| 1982 | 20 |
| 1983 | 25 |
| 1984 | 10 |
| 1985 | 17 |
| 1986 | 10 |
| 1987 | 8 |
| 1988 | 8 |
| 1989 | 6 |
| 1990 | 8 |
| 1991 | 26 |
| 1992 | 7 |
| 1997 | 5 |
| 2001 | 5 |
| 2008 | 6 |