| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.44/5 | 4.06/5 |
| Vol 3-4 | 2.48/5 | 4.19/5 |
| Vol 5-6 | 2.58/5 | 4.32/5 |
| Vol 7-8 | 2.58/5 | 4.32/5 |
| Vol 9-10 | 2.52/5 | 4.23/5 |
| Vol 11-12 | 2.60/5 | 4.40/5 |
| Vol 13-14 | 2.66/5 | 4.36/5 |
| Vol 15-16 | 2.64/5 | 4.36/5 |
| Vol 17-18 | 2.70/5 | 4.44/5 |
| Vol 19-20 | 2.68/5 | 4.41/5 |
| Vol 21-22 | 2.50/5 | 4.23/5 |
| Vol 23-24 | 2.54/5 | 4.40/5 |
| Vol 25-26 | 2.70/5 | 4.49/5 |
| Vol 27 | 2.58/5 | 4.42/5 |
| Overall | 2.59/5 | 4.49/5 |