| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.86/5 | 4.50/5 |
| Vol 3-4 | 2.17/5 | 3.78/5 |
| Vol 5-6 | 2.22/5 | 4.03/5 |
| Vol 7-8 | 2.23/5 | 4.23/5 |
| Vol 9-10 | 2.39/5 | 4.45/5 |
| Vol 11-12 | 2.20/5 | 4.09/5 |
| Vol 13-14 | 2.30/5 | 4.29/5 |
| Vol 15-16 | 2.33/5 | 4.27/5 |
| Vol 17-18 | 2.04/5 | 4.23/5 |
| Vol 19-20 | 1.85/5 | 4.19/5 |
| Vol 21-22 | 2.26/5 | 4.23/5 |
| Vol 23-24 | 2.64/5 | 4.53/5 |
| Vol 25-26 | 2.37/5 | 4.25/5 |
| Vol 27 | 3.62/5 | 4.54/5 |
| Overall | 2.35/5 | 4.54/5 |