| Value |
Category |
| 1 |
None |
| 2 |
1 year |
| 3 |
2 years |
| 4 |
3 years |
| 5 |
4 years |
| 6 |
5 years |
| 7 |
6 years |
| 8 |
7 years and over |
| 9 |
Not stated |
| 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.