| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 3.25/5 | 4.57/5 |
| Vol 3-4 | 3.86/5 | 4.62/5 |
| Vol 5-6 | 3.51/5 | 4.55/5 |
| Vol 7-8 | 3.82/5 | 4.62/5 |
| Vol 9-10 | 3.64/5 | 4.58/5 |
| Vol 11-12 | 3.75/5 | 4.60/5 |
| Vol 13-14 | 3.64/5 | 4.59/5 |
| Vol 15-16 | 4.08/5 | 4.65/5 |
| Vol 17-18 | 3.87/5 | 4.64/5 |
| Vol 19-20 | 3.92/5 | 4.59/5 |
| Vol 21-22 | 3.95/5 | 4.62/5 |
| Vol 23-24 | 3.57/5 | 4.59/5 |
| Vol 25-26 | 3.68/5 | 4.59/5 |
| Vol 27-28 | 3.58/5 | 4.55/5 |
| Vol 29-30 | 4.04/5 | 4.62/5 |
| Vol 31-32 | 3.86/5 | 4.63/5 |
| Vol 33-34 | 3.92/5 | 4.60/5 |
| Vol 35-36 | 3.89/5 | 4.65/5 |
| Vol 37 | 3.94/5 | 4.59/5 |
| Overall | 3.77/5 | 4.65/5 |