| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-2 | 2.98/5 | 4.56/5 |
| Vol 3-4 | 3.01/5 | 4.59/5 |
| Vol 5-6 | 2.92/5 | 4.41/5 |
| Vol 7-8 | 3.07/5 | 4.53/5 |
| Vol 9-10 | 2.93/5 | 4.39/5 |
| Vol 11-12 | 3.22/5 | 4.56/5 |
| Vol 13-14 | 3.06/5 | 4.50/5 |
| Vol 15-16 | 2.98/5 | 4.48/5 |
| Vol 17-18 | 3.00/5 | 4.45/5 |
| Vol 19-20 | 2.86/5 | 4.37/5 |
| Vol 21-22 | 2.94/5 | 4.45/5 |
| Vol 23-24 | 3.02/5 | 4.60/5 |
| Vol 25-26 | 2.90/5 | 4.39/5 |
| Vol 27-28 | 2.94/5 | 4.51/5 |
| Vol 29-30 | 2.95/5 | 4.37/5 |
| Vol 31-32 | 2.88/5 | 4.24/5 |
| Vol 33-34 | 2.88/5 | 4.45/5 |
| Vol 35-36 | 3.11/5 | 4.42/5 |
| Vol 37-38 | 2.95/5 | 4.52/5 |
| Overall | 2.98/5 | 4.60/5 |