| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 3.71/5 | 4.58/5 |
| Vol 3-4 | 4.05/5 | 4.61/5 |
| Vol 5-6 | 3.57/5 | 4.59/5 |
| Vol 7-8 | 4.02/5 | 4.59/5 |
| Vol 9-10 | 3.27/5 | 4.60/5 |
| Vol 11-12 | 2.77/5 | 4.50/5 |
| Vol 13-14 | 3.70/5 | 4.60/5 |
| Vol 15-16 | 4.05/5 | 4.60/5 |
| Vol 17-18 | 3.79/5 | 4.62/5 |
| Vol 19-20 | 3.56/5 | 4.60/5 |
| Vol 21-22 | 3.84/5 | 4.58/5 |
| Vol 23-24 | 4.03/5 | 4.59/5 |
| Vol 25-26 | 3.34/5 | 4.61/5 |
| Vol 27 | 2.83/5 | 4.49/5 |
| Overall | 3.62/5 | 4.62/5 |