Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Winner | Country | Winter Olympics | FIS Nordic World Ski Championships | Holmenkollen |
| --- | --- | --- | --- | --- |
| Birger Ruud | Norway | 1932, 1936 | 1931, 1932, 1935, 1936, 1937, 1948 | 1932 |
| Arnfinn Bergmann | Norway | 1952 | 1952 | 1952 |
| Antti Hyvärinen | Finland | 1956 | 1956 | 1956 |
| Helmut Recknagel | German Democratic Republic | 1960 | 1960, 1962 | 1957, 1960 |
| Toralf Engan | Norway | 1964 | 1962, 1964 | 1962 |
| Vladimir Beloussov | Soviet Union | 1968 | 1968 | 1968, 1970 |
| Karl Schnabl | Austria | 1976 | 1976 | 1976 |
| Anton Innauer | Austria | 1980 | 1980 | 1975 |
| Matti Nykänen | Finland | 1984, 1988 | 1982 | 1982 |
| Kazuyoshi Funaki | Japan | 1998 | 1999 | 1997 |
Question:
What years did Birger Ruud win the FIS Nordic World Ski Championships?
Answer:
1931, 1932, 1935, 1936, 1937, 1948