| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.78/5 | 4.56/5 |
| Vol 3-4 | 2.89/5 | 4.64/5 |
| Vol 5-6 | 3.02/5 | 4.73/5 |
| Vol 7-8 | 3.03/5 | 4.66/5 |
| Vol 9-10 | 2.87/5 | 4.72/5 |
| Vol 11-12 | 2.99/5 | 4.73/5 |
| Vol 13-14 | 3.39/5 | 4.73/5 |
| Vol 15-16 | 3.06/5 | 4.73/5 |
| Vol 17-18 | 2.86/5 | 4.66/5 |
| Vol 19-20 | 3.64/5 | 4.77/5 |
| Vol 21-22 | 3.17/5 | 4.74/5 |
| Vol 23-24 | 3.44/5 | 4.76/5 |
| Vol 25-26 | 3.06/5 | 4.70/5 |
| Vol 27-28 | 2.90/5 | 4.67/5 |
| Vol 29-30 | 4.08/5 | 4.82/5 |
| Vol 31-32 | 4.22/5 | 4.81/5 |
| Vol 33-34 | 3.22/5 | 4.74/5 |
| Vol 35-36 | 3.11/5 | 4.72/5 |
| Vol 37 | 3.45/5 | 4.71/5 |
| Overall | 3.22/5 | 4.82/5 |