| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.91/5 | 4.42/5 |
| Vol 3-4 | 3.41/5 | 4.56/5 |
| Vol 5-6 | 3.07/5 | 4.32/5 |
| Vol 7-8 | 3.54/5 | 4.50/5 |
| Vol 9-10 | 3.24/5 | 4.47/5 |
| Vol 11-12 | 3.41/5 | 4.55/5 |
| Vol 13-14 | 3.02/5 | 4.45/5 |
| Vol 15-16 | 3.53/5 | 4.60/5 |
| Vol 17-18 | 3.47/5 | 4.55/5 |
| Vol 19-20 | 3.61/5 | 4.56/5 |
| Vol 21-22 | 3.30/5 | 4.46/5 |
| Vol 23-24 | 3.59/5 | 4.51/5 |
| Vol 25-26 | 3.67/5 | 4.59/5 |
| Vol 27-28 | 3.67/5 | 4.54/5 |
| Vol 29-30 | 3.39/5 | 4.49/5 |
| Vol 31-32 | 3.32/5 | 4.42/5 |
| Vol 33-34 | 3.33/5 | 4.48/5 |
| Vol 35-36 | 3.62/5 | 4.60/5 |
| Vol 37 | 3.88/5 | 4.61/5 |
| Overall | 3.39/5 | 4.61/5 |