| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 3.02/5 | 4.72/5 |
| Vol 3-4 | 2.87/5 | 4.59/5 |
| Vol 5-6 | 3.78/5 | 4.79/5 |
| Vol 7-8 | 3.48/5 | 4.77/5 |
| Vol 9-10 | 3.85/5 | 4.79/5 |
| Vol 11-12 | 3.14/5 | 4.72/5 |
| Vol 13-14 | 4.17/5 | 4.80/5 |
| Vol 15-16 | 3.64/5 | 4.74/5 |
| Vol 17-18 | 3.31/5 | 4.68/5 |
| Vol 19-20 | 3.64/5 | 4.76/5 |
| Vol 21-22 | 3.14/5 | 4.67/5 |
| Vol 23-24 | 3.47/5 | 4.71/5 |
| Vol 25-26 | 3.43/5 | 4.72/5 |
| Vol 27-28 | 3.48/5 | 4.70/5 |
| Vol 29-30 | 4.05/5 | 4.76/5 |
| Vol 31 | 4.29/5 | 4.82/5 |
| Overall | 3.50/5 | 4.82/5 |