| Valeur | Modalité | Cas | |
|---|---|---|---|
| -1 | Non réponse | 1 |
0.1%
|
| 1975 | 1 |
0.1%
|
|
| 1987 | 1 |
0.1%
|
|
| 1995 | 1 |
0.1%
|
|
| 1997 | 1 |
0.1%
|
|
| Sysmiss | 1279 |