| Time (months) | |||
| Boat type | Status | No. of boats | Mean |
| Tug | 0 | 5 | 5.347 |
| 1 | 29 | 8.326 | |
| Supply | 0 | 32 | 5.126 |
| 1 | 162 | 5.229 | |
| Crew | 0 | 12 | 4.798 |
| 1 | 59 | 5.205 |