| Value |
Category |
| 1 |
Once a quarter |
| 2 |
Once a year |
| 3 |
Once a 2 year period |
| 4 |
None |
| 5 |
When sick |
| 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.