| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.80/5 | 4.46/5 |
| Vol 3-4 | 2.99/5 | 4.48/5 |
| Vol 5-6 | 4.01/5 | 4.59/5 |
| Vol 7-8 | 3.99/5 | 4.59/5 |
| Vol 9-10 | 3.12/5 | 4.54/5 |
| Vol 11-12 | 3.08/5 | 4.50/5 |
| Vol 13-14 | 3.85/5 | 4.59/5 |
| Vol 15-16 | 2.84/5 | 4.48/5 |
| Vol 17-18 | 2.86/5 | 4.48/5 |
| Vol 19-20 | 3.32/5 | 4.57/5 |
| Vol 21-22 | 2.97/5 | 4.46/5 |
| Vol 23-24 | 2.66/5 | 4.37/5 |
| Vol 25-26 | 2.79/5 | 4.41/5 |
| Vol 27-28 | 2.69/5 | 4.44/5 |
| Vol 29-30 | 2.71/5 | 4.43/5 |
| Vol 31 | 2.87/5 | 4.52/5 |
| Overall | 3.09/5 | 4.59/5 |