| Value |
Category |
| 1 |
always (since birth) |
| 2 |
less than one year |
| 3 |
from one to three years |
| 4 |
from three to five years |
| 5 |
more than five years |
| 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.