| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 3.94/5 | 4.58/5 |
| Vol 3-4 | 3.61/5 | 4.53/5 |
| Vol 5-6 | 2.80/5 | 4.48/5 |
| Vol 7-8 | 3.14/5 | 4.51/5 |
| Vol 9-10 | 3.20/5 | 4.53/5 |
| Vol 11-12 | 3.37/5 | 4.59/5 |
| Vol 13-14 | 3.82/5 | 4.57/5 |
| Vol 15-16 | 3.89/5 | 4.60/5 |
| Vol 17-18 | 3.11/5 | 4.49/5 |
| Vol 19-20 | 3.52/5 | 4.53/5 |
| Vol 21-22 | 3.87/5 | 4.60/5 |
| Vol 23-24 | 4.04/5 | 4.60/5 |
| Vol 25-26 | 3.28/5 | 4.53/5 |
| Vol 27 | 2.88/5 | 4.48/5 |
| Overall | 3.49/5 | 4.60/5 |