| Table 9a. Estimated observation SDs. | |||
| Index | Fleet number | Age | Estimate |
| 1 | 1 | 1 | 0.66014 |
| 2 | 1 | 2 | 0.23964 |
| 3 | 1 | 3 | 0.07674 |
| 4 | 1 | 4 | 0.07674 |
| 5 | 1 | 5 | 0.07674 |
| 6 | 1 | 6 | 0.07674 |
| 7 | 1 | 7 | 0.07674 |
| 8 | 2 | 1 | 0.62805 |
| 9 | 2 | 2 | 0.22173 |
| 10 | 2 | 3 | 0.22173 |
| 11 | 2 | 4 | 0.22173 |
| 12 | 2 | 5 | 0.22173 |
| 13 | 3 | 1 | 0.34198 |
| 14 | 3 | 2 | 0.33561 |
| 15 | 3 | 3 | 0.33561 |
| 16 | 3 | 4 | 0.33561 |