| Table 9a. Estimated observation SDs. | |||
| Index | Fleet number | Age | Estimate |
| 1 | 1 | 1 | 0.60438 |
| 2 | 1 | 2 | 0.23840 |
| 3 | 1 | 3 | 0.07513 |
| 4 | 1 | 4 | 0.07513 |
| 5 | 1 | 5 | 0.07513 |
| 6 | 1 | 6 | 0.07513 |
| 7 | 2 | 1 | 0.46844 |
| 8 | 2 | 2 | 0.23029 |
| 9 | 2 | 3 | 0.23029 |
| 10 | 2 | 4 | 0.23029 |
| 11 | 2 | 5 | 0.23029 |
| 12 | 3 | 1 | 0.35676 |
| 13 | 3 | 2 | 0.25186 |
| 14 | 3 | 3 | 0.25186 |
| 15 | 3 | 4 | 0.25186 |