| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.88/5 | 4.39/5 |
| Vol 3-4 | 3.40/5 | 4.53/5 |
| Vol 5-6 | 3.05/5 | 4.29/5 |
| Vol 7-8 | 3.51/5 | 4.47/5 |
| Vol 9-10 | 3.15/5 | 4.44/5 |
| Vol 11-12 | 3.41/5 | 4.52/5 |
| Vol 13-14 | 2.99/5 | 4.42/5 |
| Vol 15-16 | 3.54/5 | 4.57/5 |
| Vol 17-18 | 3.45/5 | 4.52/5 |
| Vol 19-20 | 3.58/5 | 4.53/5 |
| Vol 21-22 | 3.28/5 | 4.43/5 |
| Vol 23-24 | 3.50/5 | 4.48/5 |
| Vol 25-26 | 3.61/5 | 4.56/5 |
| Vol 27-28 | 3.64/5 | 4.51/5 |
| Vol 29-30 | 3.37/5 | 4.46/5 |
| Vol 31-32 | 3.28/5 | 4.39/5 |
| Vol 33-34 | 3.30/5 | 4.45/5 |
| Vol 35-36 | 3.62/5 | 4.57/5 |
| Vol 37 | 3.85/5 | 4.58/5 |
| Overall | 3.38/5 | 4.58/5 |