| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.94/5 | 4.53/5 |
| Vol 3-4 | 2.83/5 | 4.47/5 |
| Vol 5-6 | 2.70/5 | 4.48/5 |
| Vol 7-8 | 2.76/5 | 4.32/5 |
| Vol 9-10 | 2.88/5 | 4.45/5 |
| Vol 11-12 | 2.84/5 | 4.44/5 |
| Vol 13-14 | 2.90/5 | 4.46/5 |
| Vol 15-16 | 2.80/5 | 4.47/5 |
| Vol 17-18 | 2.82/5 | 4.42/5 |
| Vol 19-20 | 2.82/5 | 4.51/5 |
| Vol 21-22 | 2.84/5 | 4.53/5 |
| Vol 23-24 | 3.28/5 | 4.57/5 |
| Vol 25-26 | 3.76/5 | 4.60/5 |
| Vol 27-28 | 3.24/5 | 4.52/5 |
| Vol 29-30 | 3.96/5 | 4.65/5 |
| Overall | 3.03/5 | 4.65/5 |