| Value |
Category |
| 0 |
Never |
| 1 |
0-11 months ago |
| 2 |
12+ months ago |
| 3 |
Yes, but don't remember when |
| 4 |
Yes, but frequency in last 12 months missing |
| 9 |
|
| 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.