| Value |
Category |
| 1 |
per month |
| 2 |
Once per 3 months |
| 3 |
Once every 6 months |
| 4 |
Once a year or less |
| 5 |
Not once |
| 6 |
I do not know |
| 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.