| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-4 | 2.60/5 | 4.17/5 |
| Vol 5-8 | 2.58/5 | 4.29/5 |
| Vol 9-12 | 2.65/5 | 4.36/5 |
| Vol 13-16 | 2.64/5 | 4.14/5 |
| Vol 17-20 | 2.67/5 | 4.32/5 |
| Vol 21-24 | 2.60/5 | 4.35/5 |
| Vol 25-28 | 2.72/5 | 4.41/5 |
| Vol 29-32 | 2.86/5 | 4.42/5 |
| Vol 33-36 | 2.85/5 | 4.40/5 |
| Vol 37-40 | 2.78/5 | 4.39/5 |
| Vol 41-44 | 2.77/5 | 4.46/5 |
| Vol 45-48 | 2.93/5 | 4.49/5 |
| Vol 49-52 | 2.84/5 | 4.53/5 |
| Vol 53-56 | 2.70/5 | 4.33/5 |
| Vol 57-60 | 2.62/5 | 4.25/5 |
| Vol 61-64 | 2.68/5 | 4.35/5 |
| Vol 65-68 | 2.65/5 | 4.25/5 |
| Vol 69-72 | 2.70/5 | 4.30/5 |
| Vol 73-76 | 2.59/5 | 4.19/5 |
| Vol 77-78 | 2.60/5 | 4.03/5 |
| Overall | 2.70/5 | 4.53/5 |