| Value |
Category |
| 1 |
Formally (e.g formal set of books, computer) |
| 2 |
Informally (e.g ticks on the wall or on paper) |
| 8 |
Not applicable |
| 9 |
Unspecified |
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.