| Value | Category |
|---|---|
| -1 | Unmatched |
| 1 | Matched last, 2009 and 2010 |
| 2 | Matched last and 2009 |
| 3 | Matched last and 2010 |
| 4 | Matched 2009 and 2010 |
| 5 | Matched last only |
| 6 | Matched 2009 only |
| 7 | Matched 2010 only |
| 11 | Unexplained_In Nicola file |
| 12 | Unexplained_Not in Nicola file |
| 25 | No Schooling |
| 44 | Deceased |
| 88 | Individual or Household Refusal |