| Value |
Category |
| 1 |
at least once per year |
| 2 |
every 1-2 years |
| 3 |
every 3-5 years |
| 4 |
less than every 5 years |
| 8 |
dk/dr |
| 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.