| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-6 | 2.76/5 | 4.52/5 |
| Vol 7-12 | 2.60/5 | 4.50/5 |
| Vol 13-18 | 2.71/5 | 4.62/5 |
| Vol 19-24 | 2.63/5 | 4.52/5 |
| Vol 25-30 | 2.34/5 | 4.42/5 |
| Vol 31-36 | 2.55/5 | 4.60/5 |
| Vol 37-42 | 2.54/5 | 4.57/5 |
| Vol 43-48 | 2.59/5 | 4.49/5 |
| Vol 49-54 | 2.70/5 | 4.54/5 |
| Vol 55-60 | 2.63/5 | 4.49/5 |
| Vol 61-66 | 2.66/5 | 4.53/5 |
| Vol 67-72 | 2.85/5 | 4.54/5 |
| Vol 73-78 | 2.72/5 | 4.55/5 |
| Vol 79-84 | 2.62/5 | 4.45/5 |
| Vol 85-90 | 2.53/5 | 4.46/5 |
| Vol 91-96 | 2.68/5 | 4.50/5 |
| Vol 97-102 | 2.54/5 | 4.40/5 |
| Vol 103-108 | 2.50/5 | 4.36/5 |
| Vol 109-114 | 2.66/5 | 4.52/5 |
| Vol 115-120 | 2.52/5 | 4.44/5 |
| Vol 121-126 | 2.40/5 | 4.38/5 |
| Vol 127-131 | 2.31/5 | 4.33/5 |
| Overall | 2.59/5 | 4.62/5 |