| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 3.65/5 | 4.51/5 |
| Vol 3-4 | 3.69/5 | 4.49/5 |
| Vol 5-6 | 3.68/5 | 4.50/5 |
| Vol 7-8 | 3.74/5 | 4.52/5 |
| Vol 9-10 | 3.79/5 | 4.56/5 |
| Vol 11-12 | 3.83/5 | 4.59/5 |
| Vol 13-14 | 3.72/5 | 4.51/5 |
| Vol 15-16 | 3.84/5 | 4.58/5 |
| Vol 17-18 | 3.80/5 | 4.56/5 |
| Vol 19-20 | 3.78/5 | 4.54/5 |
| Vol 21-22 | 3.80/5 | 4.56/5 |
| Vol 23-24 | 3.75/5 | 4.55/5 |
| Vol 25-26 | 3.69/5 | 4.50/5 |
| Vol 27-28 | 3.89/5 | 4.58/5 |
| Overall | 3.76/5 | 4.59/5 |