| Value | Category | Cases | |
|---|---|---|---|
| 0 | No incentive | 0 |
0%
|
| 1 | 5$ incentive | 170 |
30.2%
|
| 2 | 10$ incentive | 70 |
12.5%
|
| 3 | 15$ incentive | 322 |
57.3%
|
| Sysmiss | 5966 |