| 1955 | 1 |
| 1956 | 4 |
| 1960 | 6 |
| 1961 | 11 |
| 1962 | 15 |
| 1963 | 19 |
| 1964 | 23 |
| 1966 | 27 |
| 1967 | 31 |
| 1968 | 34 |
| 1969 | 38 |
| 1970 | 42 |
| 1971 | 46 |
| 1972 | 50 |
| 1973 | 53 |
| 1974 | 56 |
| 1975 | 60 |
| 1976 | 64 |
| 1977 | 68 |
| 1978 | 72 |
| 1979 | 75 |
| 1980 | 79 |
| 1981 | 82 |
| 1982 | 85 |
| 1983 | 88 |
| 1984 | 91 |
| 1985 | 94 |
| 1986 | 97 |
| 1987 | 100 |
| 1988 | 103 |
| 1989 | 106 |
| 1990 | 109 |
| 1991 | 113 |
| 1992 | 116 |
| 1993 | 120 |
| 1994 | 123 |
| 1995 | 127 |
| 1996 | 131 |
| 1997 | 135 |
| 1998 | 139 |
| 1999 | 143 |