| Progress | Difficulty | Peak |
|---|---|---|
| Vol 1-3 | 3.70/5 | 4.56/5 |
| Vol 4-6 | 3.37/5 | 4.50/5 |
| Vol 7-9 | 3.84/5 | 4.53/5 |
| Vol 10-12 | 3.93/5 | 4.55/5 |
| Vol 13-15 | 3.87/5 | 4.55/5 |
| Vol 16-18 | 3.98/5 | 4.58/5 |
| Vol 19-21 | 3.88/5 | 4.57/5 |
| Vol 22-24 | 3.77/5 | 4.61/5 |
| Vol 25-27 | 3.94/5 | 4.56/5 |
| Vol 28-30 | 3.94/5 | 4.57/5 |
| Vol 31-33 | 3.96/5 | 4.59/5 |
| Vol 34-36 | 3.77/5 | 4.53/5 |
| Vol 37-39 | 3.79/5 | 4.51/5 |
| Vol 40-42 | 4.04/5 | 4.60/5 |
| Vol 43-45 | 4.02/5 | 4.59/5 |
| Vol 46-48 | 3.65/5 | 4.52/5 |
| Vol 49-51 | 4.00/5 | 4.56/5 |
| Vol 52-54 | 3.92/5 | 4.55/5 |
| Vol 55-56 | 3.93/5 | 4.59/5 |
| Overall | 3.85/5 | 4.61/5 |