| Value | Category |
|---|---|
| 01 | No income |
| 02 | 1 to 4,800 |
| 03 | 4,801 to 9,600 |
| 04 | 9,601 to 19,200 |
| 05 | 19,201 to 38,400 |
| 06 | 38,401 to 76,800 |
| 07 | 76,801 to 153,600 |
| 08 | 153,601 to 307,200 |
| 09 | 307,201 to 614,400 |
| 10 | 614,401 to 1,228,800 |
| 11 | 1,228,801 to 2,457,600 |
| 12 | 2,457,601 or more |
| 98 | Unknown |
| 99 | NIU (not in universe) |