| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.44/5 | 4.50/5 |
| Vol 3-4 | 2.77/5 | 4.51/5 |
| Vol 5-6 | 2.85/5 | 4.58/5 |
| Vol 7-8 | 2.79/5 | 4.45/5 |
| Vol 9-10 | 3.01/5 | 4.56/5 |
| Vol 11-12 | 3.06/5 | 4.56/5 |
| Vol 13-14 | 2.97/5 | 4.58/5 |
| Vol 15-16 | 3.41/5 | 4.58/5 |
| Vol 17-18 | 3.26/5 | 4.64/5 |
| Vol 19-20 | 3.20/5 | 4.56/5 |
| Vol 21-22 | 3.87/5 | 4.62/5 |
| Vol 23-24 | 3.93/5 | 4.64/5 |
| Vol 25-26 | 3.98/5 | 4.64/5 |
| Vol 27 | 3.77/5 | 4.58/5 |
| Overall | 3.19/5 | 4.64/5 |