| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-3 | 2.70/5 | 4.19/5 |
| Vol 4-6 | 2.90/5 | 4.51/5 |
| Vol 7-9 | 2.82/5 | 4.43/5 |
| Vol 10-12 | 2.99/5 | 4.40/5 |
| Vol 13-15 | 2.93/5 | 4.45/5 |
| Vol 16-18 | 3.00/5 | 4.42/5 |
| Vol 19-21 | 3.22/5 | 4.51/5 |
| Vol 22-24 | 2.97/5 | 4.46/5 |
| Vol 25-27 | 3.17/5 | 4.47/5 |
| Vol 28-30 | 3.27/5 | 4.52/5 |
| Vol 31-33 | 2.93/5 | 4.38/5 |
| Vol 34-36 | 2.94/5 | 4.39/5 |
| Vol 37-39 | 3.06/5 | 4.48/5 |
| Vol 40-42 | 3.06/5 | 4.48/5 |
| Vol 43-45 | 2.83/5 | 4.41/5 |
| Vol 46-48 | 3.06/5 | 4.46/5 |
| Vol 49-51 | 3.28/5 | 4.57/5 |
| Vol 52-54 | 3.17/5 | 4.51/5 |
| Vol 55-57 | 3.28/5 | 4.54/5 |
| Vol 58-60 | 3.39/5 | 4.55/5 |
| Vol 61 | 3.83/5 | 4.58/5 |
| Overall | 3.06/5 | 4.58/5 |