| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 3.05/5 | 4.37/5 |
| Vol 3-4 | 3.66/5 | 4.42/5 |
| Vol 5-6 | 3.31/5 | 4.35/5 |
| Vol 7-8 | 3.62/5 | 4.42/5 |
| Vol 9-10 | 3.44/5 | 4.38/5 |
| Vol 11-12 | 3.55/5 | 4.40/5 |
| Vol 13-14 | 3.44/5 | 4.39/5 |
| Vol 15-16 | 3.88/5 | 4.45/5 |
| Vol 17-18 | 3.67/5 | 4.44/5 |
| Vol 19-20 | 3.72/5 | 4.39/5 |
| Vol 21-22 | 3.75/5 | 4.42/5 |
| Vol 23-24 | 3.37/5 | 4.39/5 |
| Vol 25-26 | 3.48/5 | 4.39/5 |
| Vol 27-28 | 3.38/5 | 4.35/5 |
| Vol 29-30 | 3.84/5 | 4.42/5 |
| Vol 31-32 | 3.66/5 | 4.43/5 |
| Vol 33-34 | 3.72/5 | 4.40/5 |
| Vol 35-36 | 3.69/5 | 4.45/5 |
| Vol 37 | 3.74/5 | 4.39/5 |
| Overall | 3.57/5 | 4.45/5 |