| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-3 | 3.91/5 | 4.53/5 |
| Vol 4-6 | 3.73/5 | 4.43/5 |
| Vol 7-9 | 3.97/5 | 4.52/5 |
| Vol 10-12 | 3.95/5 | 4.52/5 |
| Vol 13-15 | 3.89/5 | 4.49/5 |
| Vol 16-18 | 3.88/5 | 4.50/5 |
| Vol 19-21 | 3.89/5 | 4.48/5 |
| Vol 22-24 | 3.88/5 | 4.51/5 |
| Vol 25-27 | 3.87/5 | 4.52/5 |
| Vol 28-30 | 3.81/5 | 4.46/5 |
| Vol 31-33 | 3.66/5 | 4.44/5 |
| Vol 34-36 | 3.67/5 | 4.44/5 |
| Vol 37-39 | 3.77/5 | 4.44/5 |
| Vol 40-42 | 3.83/5 | 4.47/5 |
| Vol 43-45 | 3.67/5 | 4.40/5 |
| Vol 46-48 | 3.81/5 | 4.46/5 |
| Vol 49-51 | 3.80/5 | 4.47/5 |
| Vol 52-54 | 3.85/5 | 4.48/5 |
| Overall | 3.82/5 | 4.53/5 |