| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-6 | 2.98/5 | 4.75/5 |
| Vol 7-12 | 2.83/5 | 4.73/5 |
| Vol 13-18 | 2.96/5 | 4.85/5 |
| Vol 19-24 | 2.87/5 | 4.75/5 |
| Vol 25-30 | 2.57/5 | 4.65/5 |
| Vol 31-36 | 2.75/5 | 4.83/5 |
| Vol 37-42 | 2.74/5 | 4.80/5 |
| Vol 43-48 | 2.83/5 | 4.72/5 |
| Vol 49-54 | 2.92/5 | 4.77/5 |
| Vol 55-60 | 2.85/5 | 4.72/5 |
| Vol 61-66 | 2.88/5 | 4.76/5 |
| Vol 67-72 | 3.07/5 | 4.77/5 |
| Vol 73-78 | 2.94/5 | 4.78/5 |
| Vol 79-84 | 2.85/5 | 4.68/5 |
| Vol 85-90 | 2.74/5 | 4.69/5 |
| Vol 91-96 | 2.91/5 | 4.73/5 |
| Vol 97-102 | 2.77/5 | 4.63/5 |
| Vol 103-108 | 2.73/5 | 4.59/5 |
| Vol 109-114 | 2.89/5 | 4.75/5 |
| Vol 115-120 | 2.75/5 | 4.67/5 |
| Vol 121-126 | 2.63/5 | 4.61/5 |
| Vol 127-131 | 2.53/5 | 4.56/5 |
| Overall | 2.83/5 | 4.85/5 |