| Value | Category |
|---|---|
| 1 | 1 - 7 (i.e. 1 or less per day) |
| 2 | 22 - 42 (i.e. 6 or less per day, but more than 3 per day) |
| 3 | 43 - 70 (i.e. 10 or less per day but more than 6 per day) |
| 4 | 70+ (i.e. more than 10 a day) |
| 5 | 8 - 21 (i.e. 3 or less per day, but more than 1 per day) |
| Sysmiss |