| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 1.52/5 | 2.85/5 |
| Vol 3-4 | 1.37/5 | 2.43/5 |
| Vol 5-6 | 1.52/5 | 2.83/5 |
| Vol 7-8 | 1.57/5 | 2.79/5 |
| Vol 9-10 | 1.37/5 | 2.50/5 |
| Vol 11-12 | 1.45/5 | 2.57/5 |
| Vol 13-14 | 1.38/5 | 2.68/5 |
| Vol 15-16 | 1.45/5 | 2.75/5 |
| Vol 17-18 | 1.34/5 | 2.30/5 |
| Vol 19-20 | 1.35/5 | 2.50/5 |
| Vol 21-22 | 1.35/5 | 2.54/5 |
| Vol 23-24 | 1.37/5 | 2.72/5 |
| Vol 25-26 | 1.42/5 | 2.65/5 |
| Vol 27-28 | 1.46/5 | 3.17/5 |
| Vol 29-30 | 1.40/5 | 2.77/5 |
| Vol 31 | 1.46/5 | 2.69/5 |
| Overall | 1.42/5 | 3.17/5 |