Osservazioni fatte in 2000 anni
| anno | -127 | +960 | 1430 | 1590 | 1603 | 1660 | 1700 | 1800 | 1840 | 1860 | 1880 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 2 | 2 | 2.0 | |
| 3 | 2.3 | 3 | 2 | 2 | 2 | 2 | 2 | 2.3 | 2.3 | 2.2 | |
| 3 | 3 | 3 | 2 | 2 | 2 | 2.5 | 3.4 | 2.3 | 2.3 | 2.1 | |
| 3 | 3.4 | 0 | 3 | 3 | 3 | 3 | 3 | 3.4 | 3.4 | 3.3 | |
| 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4.5 | 4.3 | |
| 4 | 4.5 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4.5 | 4.3 | |
| 4 | 5.4 | 5 | 5 | 4 | 4 | 4.5 | 5 | 5 | 4.5 | 4.4 | |
| 4 | 4.5 | 4 | 4 | 4 | 5 | 4.5 | 5 | 5.4 | 5.6 | 5.4 | |
| 4 | 4.3 | 4 | 4 | 4 | 4 | 4 | 7 | 4 | 4 | 4.5 | |
| 4 | 4.3 | 4 | 4 | 4 | 4 | 4 | 5 | 4 | 4.5 | 4.5 | |
| 4 | 4.3 | 4 | 4 | 4 | 4 | 4 | 4.5 | 4 | 4 | 4.4 | |
| 4 | 4 | 4 | 4 | 4 | 3 | 3.5 | 4 | 4 | 4 | 4.3 | |
| 4 | 4.5 | 4 | 4 | 4 | 4 | 4 | 4 | 4.5 | 4.5 | 4.5 | |
| 0 | 0 | 0 | 0 | 4 | 5 | 4.5 | 5 | 5 | 5 | 5.0 | |
| 3 | 4.3 | 4 | 0 | 4 | 4 | 3.5 | 4 | 4.3 | 4.3 | 4.0 | |
| 0 | 0 | 4 | 5 | 5 | 4 | 4.5 | 4.5 | 4 | 4 | 4.3 | |
| 5 | 5.6 | 5 | 5 | 5 | 5 | 5 | 5.6 | 6 | 6.5 | 6.0 | |
| 4 | 4.5 | 4 | 5 | 5 | 5 | 5 | 5.6 | 4.5 | 4.5 | 4.7 | |
| 50 | 4 | 4 | 4.3 | 5 | 5 | 6 | 5.8 | 5 | 4.5 | 4 | 4.6 | |
| 4 | 4.3 | 4 | 5 | 5 | 5 | 4 | 5.6 | 6 | 6.5 | 5.5 | |
| 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 4.5 | 4.5 | 4.5 | |
| 5 | 6 | 5 | 0 | 5 | 0 | 6 | 6 | 5.6 | 6.5 | 5.6 | |
| 0 | 0 | 0 | 5 | 5 | 6 | 5.5 | 5 | 5 | 6.5 | 5.7 | |
| 0 | 0 | 0 | 0 | 6 | 5 | 5 | 5.6 | 5 | 5 | 4.7 | |
| A | 0 | 0 | 5 | 0 | 6 | 5 | 5 | 5.6 | 6 | 6 | 6.0 | |
| b | 0 | 0 | 0 | 0 | 6 | 0 | 6 | 6 | 5.6 | 5.6 | 5.5 | |
| c | 0 | 0 | 0 | 0 | 6 | 0 | 6 | 6 | 5.6 | 5.6 | 6.0 | |
| 53 | 0 | 0 | 0 | 0 | 0 | 5 | 5 | 5.6 | 5 | 5.6 | 4.8 | |
| 3 | 0 | 0 | 0 | 0 | 0 | 6 | 6 | 6 | 5.6 | 5 | 5.5 | |
| 7 | 0 | 0 | 0 | 0 | 0 | 6 | 5.5 | 5 | 5 | 5 | 5.4 | |
| 41 | 0 | 0 | 0 | 0 | 0 | 5 | 5 | 5.6 | 5 | 5 | 5.4 | |
| Neb. | 0 | Neb. | 0 | 0 | 0 | Neb. | Neb. | Neb. | Neb. | Neb. | Neb. |