| Value |
Category |
| -999999999 |
missing |
| 1 |
Less than 1 year |
| 2 |
1 year |
| 3 |
2 years |
| 4 |
more than 2 years |
| 5 |
Still attending |
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.