| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.61/5 | 4.40/5 |
| Vol 3-4 | 2.42/5 | 4.36/5 |
| Vol 5-6 | 2.66/5 | 4.42/5 |
| Vol 7-8 | 2.74/5 | 4.46/5 |
| Vol 9-10 | 2.60/5 | 4.42/5 |
| Vol 11-12 | 2.58/5 | 4.41/5 |
| Vol 13-14 | 2.78/5 | 4.45/5 |
| Vol 15-16 | 2.84/5 | 4.47/5 |
| Vol 17-18 | 2.46/5 | 4.27/5 |
| Vol 19-20 | 2.51/5 | 4.29/5 |
| Vol 21-22 | 2.84/5 | 4.53/5 |
| Vol 23-24 | 3.01/5 | 4.50/5 |
| Vol 25-26 | 3.18/5 | 4.56/5 |
| Vol 27-28 | 2.56/5 | 4.33/5 |
| Overall | 2.70/5 | 4.56/5 |