| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-6 | 3.83/5 | 4.64/5 |
| Vol 7-12 | 3.62/5 | 4.65/5 |
| Vol 13-18 | 3.75/5 | 4.66/5 |
| Vol 19-24 | 3.80/5 | 4.61/5 |
| Vol 25-30 | 3.05/5 | 4.56/5 |
| Vol 31-36 | 3.57/5 | 4.64/5 |
| Vol 37-42 | 3.32/5 | 4.59/5 |
| Vol 43-48 | 3.28/5 | 4.65/5 |
| Vol 49-54 | 3.35/5 | 4.61/5 |
| Vol 55-60 | 3.01/5 | 4.56/5 |
| Vol 61-66 | 3.32/5 | 4.57/5 |
| Vol 67-72 | 3.07/5 | 4.62/5 |
| Vol 73-78 | 3.34/5 | 4.59/5 |
| Vol 79-84 | 3.21/5 | 4.56/5 |
| Vol 85-90 | 3.23/5 | 4.59/5 |
| Vol 91-96 | 3.02/5 | 4.53/5 |
| Vol 97-102 | 3.39/5 | 4.62/5 |
| Vol 103-108 | 2.97/5 | 4.58/5 |
| Vol 109-114 | 3.01/5 | 4.57/5 |
| Vol 115-120 | 2.84/5 | 4.53/5 |
| Vol 121-126 | 3.18/5 | 4.60/5 |
| Vol 127-132 | 3.06/5 | 4.61/5 |
| Vol 133-138 | 2.95/5 | 4.55/5 |
| Vol 139-144 | 2.77/5 | 4.52/5 |
| Vol 145-146 | 2.36/5 | 4.30/5 |
| Overall | 3.26/5 | 4.66/5 |