| Value |
Category |
| 1 |
Weekly |
| 2 |
Monthly |
| 3 |
Every two months |
| 4 |
Every six months |
| 5 |
Once per year |
| 6 |
Never |
| 7 |
Not stated |
| 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.