| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 3.21/5 | 4.06/5 |
| Vol 3-4 | 3.24/5 | 4.05/5 |
| Vol 5-6 | 3.20/5 | 4.11/5 |
| Vol 7-8 | 3.19/5 | 4.14/5 |
| Vol 9-10 | 3.38/5 | 4.30/5 |
| Vol 11-12 | 3.42/5 | 4.30/5 |
| Vol 13-14 | 3.26/5 | 4.28/5 |
| Vol 15-16 | 3.33/5 | 4.12/5 |
| Vol 17-18 | 3.23/5 | 4.13/5 |
| Vol 19-20 | 3.30/5 | 4.24/5 |
| Vol 21-22 | 3.28/5 | 4.32/5 |
| Vol 23-24 | 3.20/5 | 4.00/5 |
| Vol 25-26 | 3.34/5 | 4.29/5 |
| Vol 27-28 | 3.31/5 | 4.25/5 |
| Vol 29-30 | 3.40/5 | 4.29/5 |
| Overall | 3.29/5 | 4.32/5 |