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Contingency table of day-to-day change of mean atmospheric pressure (ΔP)
| Quintiles of ΔP | Days | |
| 0 Events | 1 Event | |
| 1 (ΔP < -2.5 hPa) | 349 | 16 |
| 2 (-2.5 hPa ≤ ΔP < -0.7 hPa) | 346 | 19 |
| 3 (-0.7 hPa ≤ ΔP < 0.7 hPa) | 351 | 14 |
| 4 (0.7 hPa ≤ ΔP < 2.5 hPa) | 352 | 13 |
| 5 (ΔP ≥ 2.5 hPa) | 345 | 20 |
