| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-6 | 3.98/5 | 4.79/5 |
| Vol 7-12 | 3.77/5 | 4.80/5 |
| Vol 13-18 | 3.90/5 | 4.81/5 |
| Vol 19-24 | 3.95/5 | 4.76/5 |
| Vol 25-30 | 3.20/5 | 4.71/5 |
| Vol 31-36 | 3.72/5 | 4.79/5 |
| Vol 37-42 | 3.47/5 | 4.74/5 |
| Vol 43-48 | 3.43/5 | 4.80/5 |
| Vol 49-54 | 3.50/5 | 4.76/5 |
| Vol 55-60 | 3.16/5 | 4.71/5 |
| Vol 61-66 | 3.47/5 | 4.72/5 |
| Vol 67-72 | 3.22/5 | 4.77/5 |
| Vol 73-78 | 3.49/5 | 4.74/5 |
| Vol 79-84 | 3.36/5 | 4.71/5 |
| Vol 85-90 | 3.38/5 | 4.74/5 |
| Vol 91-96 | 3.17/5 | 4.68/5 |
| Vol 97-102 | 3.54/5 | 4.77/5 |
| Vol 103-108 | 3.12/5 | 4.73/5 |
| Vol 109-114 | 3.16/5 | 4.72/5 |
| Vol 115-120 | 2.99/5 | 4.68/5 |
| Vol 121-126 | 3.33/5 | 4.75/5 |
| Vol 127-132 | 3.21/5 | 4.76/5 |
| Vol 133-138 | 3.10/5 | 4.70/5 |
| Vol 139-144 | 2.92/5 | 4.67/5 |
| Vol 145-146 | 2.51/5 | 4.45/5 |
| Overall | 3.41/5 | 4.81/5 |