| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.25/5 | 3.59/5 |
| Vol 3-4 | 2.49/5 | 3.67/5 |
| Vol 5-6 | 2.46/5 | 3.59/5 |
| Vol 7-8 | 2.50/5 | 3.73/5 |
| Vol 9-10 | 2.47/5 | 3.47/5 |
| Vol 11-12 | 2.49/5 | 3.45/5 |
| Vol 13-14 | 2.36/5 | 3.13/5 |
| Vol 15-16 | 2.44/5 | 3.49/5 |
| Vol 17-18 | 2.36/5 | 3.23/5 |
| Vol 19-20 | 2.36/5 | 3.15/5 |
| Vol 21-22 | 2.38/5 | 3.17/5 |
| Vol 23-24 | 2.32/5 | 2.80/5 |
| Vol 25-26 | 2.41/5 | 3.36/5 |
| Vol 27-28 | 2.36/5 | 3.11/5 |
| Vol 29-30 | 2.34/5 | 3.06/5 |
| Vol 31-32 | 2.30/5 | 2.72/5 |
| Vol 33 | 2.39/5 | 3.32/5 |
| Overall | 2.39/5 | 3.73/5 |