| Value |
Category |
| 1 |
Month and year |
| 2 |
Month and age |
| 3 |
Year and age |
| 4 |
Year and age/age ignored |
| 5 |
Year |
| 6 |
Age |
| 7 |
Month |
| 8 |
None |
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.