| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.30/5 | 3.76/5 |
| Vol 3-4 | 2.39/5 | 3.60/5 |
| Vol 5-6 | 2.57/5 | 3.84/5 |
| Vol 7-8 | 2.66/5 | 3.73/5 |
| Vol 9-10 | 2.43/5 | 3.52/5 |
| Vol 11-12 | 2.54/5 | 3.57/5 |
| Vol 13-14 | 2.48/5 | 3.50/5 |
| Vol 15-16 | 2.37/5 | 3.50/5 |
| Vol 17-18 | 2.37/5 | 3.12/5 |
| Vol 19-20 | 2.48/5 | 3.62/5 |
| Vol 21-22 | 2.37/5 | 3.29/5 |
| Vol 23-24 | 2.37/5 | 3.27/5 |
| Vol 25-26 | 2.39/5 | 3.41/5 |
| Vol 27-28 | 2.32/5 | 2.87/5 |
| Vol 29-30 | 2.33/5 | 3.06/5 |
| Vol 31-32 | 2.36/5 | 3.36/5 |
| Vol 33-34 | 2.33/5 | 3.14/5 |
| Vol 35-36 | 2.30/5 | 2.76/5 |
| Vol 37 | 2.29/5 | 2.72/5 |
| Overall | 2.41/5 | 3.84/5 |