| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.74/5 | 4.40/5 |
| Vol 3-4 | 2.49/5 | 4.23/5 |
| Vol 5-6 | 2.44/5 | 4.30/5 |
| Vol 7-8 | 2.46/5 | 4.09/5 |
| Vol 9-10 | 2.10/5 | 4.06/5 |
| Vol 11-12 | 2.52/5 | 4.30/5 |
| Vol 13-14 | 2.28/5 | 4.00/5 |
| Vol 15-16 | 2.37/5 | 4.23/5 |
| Vol 17-18 | 2.28/5 | 4.23/5 |
| Vol 19-20 | 2.35/5 | 4.09/5 |
| Vol 21-22 | 2.24/5 | 4.03/5 |
| Vol 23-24 | 2.30/5 | 4.17/5 |
| Vol 25-26 | 2.66/5 | 4.19/5 |
| Vol 27-28 | 2.42/5 | 4.32/5 |
| Overall | 2.40/5 | 4.40/5 |