| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 3.56/5 | 4.42/5 |
| Vol 3-4 | 3.60/5 | 4.40/5 |
| Vol 5-6 | 3.59/5 | 4.41/5 |
| Vol 7-8 | 3.65/5 | 4.43/5 |
| Vol 9-10 | 3.70/5 | 4.47/5 |
| Vol 11-12 | 3.74/5 | 4.50/5 |
| Vol 13-14 | 3.63/5 | 4.42/5 |
| Vol 15-16 | 3.75/5 | 4.49/5 |
| Vol 17-18 | 3.71/5 | 4.47/5 |
| Vol 19-20 | 3.69/5 | 4.45/5 |
| Vol 21-22 | 3.71/5 | 4.47/5 |
| Vol 23-24 | 3.66/5 | 4.46/5 |
| Vol 25-26 | 3.60/5 | 4.41/5 |
| Vol 27-28 | 3.80/5 | 4.49/5 |
| Overall | 3.67/5 | 4.50/5 |