| Table 9a. Estimated observation SDs. | |||
| Index | Fleet number | Age | Estimate |
| 1 | 1 | 1 | 0.61517 |
| 2 | 1 | 2 | 0.23582 |
| 3 | 1 | 3 | 0.13540 |
| 4 | 1 | 4 | 0.13540 |
| 5 | 1 | 5 | 0.13540 |
| 6 | 1 | 6 | 0.13540 |
| 7 | 1 | 7 | 0.13540 |
| 8 | 1 | 8 | 0.13540 |
| 9 | 1 | 9 | 0.13540 |
| 10 | 2 | 1 | 0.45748 |
| 11 | 2 | 2 | 0.21235 |
| 12 | 2 | 3 | 0.21235 |
| 13 | 2 | 4 | 0.21235 |
| 14 | 2 | 5 | 0.21235 |
| 15 | 3 | 1 | 0.35166 |
| 16 | 3 | 2 | 0.23499 |
| 17 | 3 | 3 | 0.23499 |
| 18 | 3 | 4 | 0.23499 |