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:
| District | Incumbent | Party | First elected | Result | Candidates |
| --- | --- | --- | --- | --- | --- |
| Louisiana 1 | F. Edward Hebert | Democratic | 1940.0 | Re-elected | F. Edward Hebert (D) Unopposed |
| Louisiana 4 | Joe Waggonner | Democratic | 1961.0 | Re-elected | Joe Waggonner (D) Unopposed |
| Louisiana 5 | Otto Passman | Democratic | 1946.0 | Re-elected | Otto Passman (D) Unopposed |
| Louisiana 6 | John Rarick | Democratic | 1966.0 | Lost renomination Republican gain | Henson Moore (R) 54.1% Jeff La Caze (D) 45.9% |
| Louisiana 7 | John Breaux | Democratic | 1972.0 | Re-elected | John Breaux (D) 89.3% Jeremy J. Millett (I) 10.7% |
Question:
What year was Otto Passman (d) unopposed first elected?
Answer:
1946.0