| Value |
Category |
| 1 |
1 More than once |
| 2 |
2 Once |
| 3 |
3 None, but I wanted to participate |
| 4 |
4 None, and I did not want to participate |
| 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.