| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.52/5 | 3.99/5 |
| Vol 3-4 | 2.70/5 | 3.90/5 |
| Vol 5-6 | 2.74/5 | 3.88/5 |
| Vol 7-8 | 2.67/5 | 3.74/5 |
| Vol 9-10 | 2.75/5 | 3.79/5 |
| Vol 11-12 | 2.78/5 | 3.87/5 |
| Vol 13-14 | 2.61/5 | 3.41/5 |
| Vol 15-16 | 2.68/5 | 3.72/5 |
| Vol 17-18 | 2.64/5 | 3.64/5 |
| Vol 19-20 | 2.58/5 | 3.23/5 |
| Vol 21-22 | 2.64/5 | 3.37/5 |
| Vol 23-24 | 2.60/5 | 3.13/5 |
| Vol 25-26 | 2.64/5 | 3.43/5 |
| Vol 27-28 | 2.62/5 | 3.32/5 |
| Vol 29-30 | 2.63/5 | 3.32/5 |
| Vol 31-32 | 2.58/5 | 2.99/5 |
| Vol 33 | 2.66/5 | 3.59/5 |
| Overall | 2.65/5 | 3.99/5 |