| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.50/5 | 4.41/5 |
| Vol 3-4 | 2.32/5 | 4.42/5 |
| Vol 5-6 | 2.93/5 | 4.46/5 |
| Vol 7-8 | 3.35/5 | 4.53/5 |
| Vol 9-10 | 3.58/5 | 4.56/5 |
| Vol 11-12 | 3.18/5 | 4.54/5 |
| Vol 13-14 | 3.18/5 | 4.52/5 |
| Vol 15-16 | 3.23/5 | 4.60/5 |
| Vol 17-18 | 3.67/5 | 4.59/5 |
| Vol 19-20 | 3.68/5 | 4.59/5 |
| Vol 21-22 | 3.50/5 | 4.60/5 |
| Vol 23-24 | 3.44/5 | 4.59/5 |
| Vol 25-26 | 2.98/5 | 4.48/5 |
| Vol 27-28 | 3.42/5 | 4.64/5 |
| Vol 29-30 | 2.68/5 | 4.40/5 |
| Vol 31-32 | 3.39/5 | 4.60/5 |
| Vol 33 | 3.17/5 | 4.47/5 |
| Overall | 3.19/5 | 4.64/5 |