| Value |
Category |
| -9 |
Don't know (spontaneous) |
| 1 |
One hour or less |
| 2 |
|
| 3 |
|
| 4 |
|
| 5 |
|
| 16 |
|
| 24 |
|
| 30 |
|
| 42 |
|
| 78 |
|
| 144 |
|
| 168 |
|
| Sysmiss |
|
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.