| Value |
Category |
| 1 |
no test |
| 2 |
once per year |
| 3 |
once per term |
| 4 |
two or three times per term |
| 5 |
two or three times per month |
| 6 |
once or more per week |
| 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.