| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-3 | 2.87/5 | 4.36/5 |
| Vol 4-6 | 3.07/5 | 4.68/5 |
| Vol 7-9 | 2.99/5 | 4.60/5 |
| Vol 10-12 | 3.16/5 | 4.57/5 |
| Vol 13-15 | 3.09/5 | 4.62/5 |
| Vol 16-18 | 3.16/5 | 4.59/5 |
| Vol 19-21 | 3.39/5 | 4.68/5 |
| Vol 22-24 | 3.14/5 | 4.63/5 |
| Vol 25-27 | 3.34/5 | 4.64/5 |
| Vol 28-30 | 3.43/5 | 4.69/5 |
| Vol 31-33 | 3.10/5 | 4.55/5 |
| Vol 34-36 | 3.11/5 | 4.56/5 |
| Vol 37-39 | 3.21/5 | 4.65/5 |
| Vol 40-42 | 3.25/5 | 4.65/5 |
| Vol 43-45 | 2.99/5 | 4.58/5 |
| Vol 46-48 | 3.25/5 | 4.63/5 |
| Vol 49-51 | 3.45/5 | 4.74/5 |
| Vol 52-54 | 3.34/5 | 4.68/5 |
| Vol 55-57 | 3.44/5 | 4.71/5 |
| Vol 58-60 | 3.51/5 | 4.72/5 |
| Vol 61 | 4.00/5 | 4.75/5 |
| Overall | 3.21/5 | 4.75/5 |