| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-4 | 2.84/5 | 4.41/5 |
| Vol 5-8 | 2.82/5 | 4.53/5 |
| Vol 9-12 | 2.89/5 | 4.60/5 |
| Vol 13-16 | 2.87/5 | 4.38/5 |
| Vol 17-20 | 2.91/5 | 4.56/5 |
| Vol 21-24 | 2.85/5 | 4.59/5 |
| Vol 25-28 | 2.96/5 | 4.65/5 |
| Vol 29-32 | 3.10/5 | 4.66/5 |
| Vol 33-36 | 3.09/5 | 4.64/5 |
| Vol 37-40 | 3.02/5 | 4.63/5 |
| Vol 41-44 | 3.02/5 | 4.70/5 |
| Vol 45-48 | 3.17/5 | 4.73/5 |
| Vol 49-52 | 3.10/5 | 4.77/5 |
| Vol 53-56 | 2.93/5 | 4.57/5 |
| Vol 57-60 | 2.86/5 | 4.49/5 |
| Vol 61-64 | 2.92/5 | 4.59/5 |
| Vol 65-68 | 2.91/5 | 4.49/5 |
| Vol 69-72 | 2.94/5 | 4.54/5 |
| Vol 73-76 | 2.83/5 | 4.43/5 |
| Vol 77-78 | 2.84/5 | 4.27/5 |
| Overall | 2.94/5 | 4.77/5 |