| 差值 | 样本数 | 百分比 | 累计百分比 |
| 0 | 557 | 49.8 | 49.8 |
| −1 | 185 | 16.5 | 66.3 |
| 1 | 205 | 18.3 | 84.6 |
| −2 | 58 | 5.2 | 89.8 |
| 2 | 111 | 9.9 | 99.7 |
| 3 | 3 | 0.3 | 100.0 |
| 总计 | 1119 | 100.0 |
|