| Value |
Category |
| 0 |
Less than a year |
| 1 |
1st year |
| 2 |
2nd year |
| 3 |
3rd year |
| 4 |
4th year |
| 5 |
5th year |
| 6 |
6th year |
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.