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Atmospheric oxygen level estimates based on the discrete method.
| Group | Age | 5 percentiles | 10 percentiles | 15 percentiles |
|---|---|---|---|---|
| pO2 (% PAL) | pO2 (% PAL) | pO2 (% PAL) | ||
| Paleoproterozoic | 2500–1600 Ma | 1.0 | 1.6 | 2.4 |
| Mesoproterozoic—early Neoproterozoic | 1600–650 Ma | 0.8 | 1.6 | 2.4 |
| late Neoproterozoic—early Paleozoic | 650–400 Ma | 2.4 | 5.2 | 5.5 |
| middle Paleozoic to modern | 400–0 Ma | 100 | 100 | 100 |
We use 10th percentiles to represent the best estimates, and 5th and 15th percentiles to estimate the lower and upper bounds.
