| Value | Category |
|---|---|
| -9 | Do not know |
| -8 | Refused |
| 96 | Through shipment |
| 300 | |
| 555 | More than 20 |
| 999 | N/A |
| 1000 | |
| 1200 | |
| 2000 | |
| 3000 | |
| 4000 | |
| 4200 | |
| 5000 | |
| 6000 | |
| 7000 | |
| 8000 | |
| 10000 | |
| 13000 | |
| 15000 | |
| 20000 | |
| 25000 | |
| 30000 | |
| 38000 | |
| 40000 | |
| 50000 | |
| 60000 | |
| 100000 | |
| 120000 | |
| 130000 | |
| 150000 | |
| 200000 | |
| 300000 | |
| 500000 | |
| 1600000 | |
| Sysmiss |