| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.74/5 | 4.60/5 |
| Vol 3-4 | 3.22/5 | 4.64/5 |
| Vol 5-6 | 3.25/5 | 4.63/5 |
| Vol 7-8 | 3.91/5 | 4.73/5 |
| Vol 9-10 | 4.12/5 | 4.72/5 |
| Vol 11-12 | 3.36/5 | 4.65/5 |
| Vol 13-14 | 4.11/5 | 4.69/5 |
| Vol 15-16 | 3.60/5 | 4.66/5 |
| Vol 17-18 | 3.51/5 | 4.67/5 |
| Vol 19-20 | 2.75/5 | 4.54/5 |
| Vol 21-22 | 3.97/5 | 4.72/5 |
| Vol 23-24 | 3.79/5 | 4.69/5 |
| Vol 25-26 | 4.17/5 | 4.71/5 |
| Vol 27-28 | 3.10/5 | 4.62/5 |
| Vol 29-30 | 2.99/5 | 4.62/5 |
| Vol 31-32 | 3.43/5 | 4.66/5 |
| Vol 33-34 | 3.64/5 | 4.68/5 |
| Vol 35-36 | 2.54/5 | 4.51/5 |
| Vol 37 | 3.31/5 | 4.60/5 |
| Overall | 3.42/5 | 4.73/5 |