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:
| Date | Number | Type | Captain | Casualties |
| --- | --- | --- | --- | --- |
| 16 Oct 1943 | U-470 | VIIC | O/L Grave | 46.0 |
| 16 Oct | U-964 | VIIC | O/L Hummerjohann | 47.0 |
| 16 Oct | U-844 | IXC | O/L Moller | 53.0 |
| 17 Oct | U-540 | IXC | K/L Kasch | 55.0 |
| 17 Oct | U-631 | VIIC | O/L Kruger | 53.0 |
| 17 Oct | U-841 | IXC | K/L Bender | 26.0 |
Question:
What is the average number of casualties for the convoy with a number of U-844?
Answer:
53.0