| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.70/5 | 4.26/5 |
| Vol 3-4 | 2.64/5 | 4.40/5 |
| Vol 5-6 | 2.75/5 | 4.37/5 |
| Vol 7-8 | 2.83/5 | 4.53/5 |
| Vol 9-10 | 2.79/5 | 4.50/5 |
| Vol 11-12 | 2.81/5 | 4.42/5 |
| Vol 13-14 | 3.02/5 | 4.67/5 |
| Vol 15-16 | 2.82/5 | 4.48/5 |
| Vol 17-18 | 2.74/5 | 4.56/5 |
| Vol 19-20 | 2.87/5 | 4.48/5 |
| Vol 21-22 | 2.99/5 | 4.63/5 |
| Vol 23-24 | 2.94/5 | 4.64/5 |
| Vol 25-26 | 2.83/5 | 4.53/5 |
| Vol 27-28 | 2.72/5 | 4.40/5 |
| Overall | 2.82/5 | 4.67/5 |