| Value |
Category |
| -96 |
Other (specify) |
| 1 |
Every month |
| 2 |
Once every several months |
| 3 |
No fixed intervals of billing |
| 11 |
.O |
| 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.