| Conceptiona | N (%)b | Dioxin | N (%)c |
| some before | 1679 (64.3) | measured | 1294 (77.1) |
|
|
| missing | 385 (22.9) |
| some after | 1497 (57.3) | measured | 1160 (77.5) |
|
|
| missing | 337 (22.5) |
| some both | 553 (21.5) | measured | 416 (73.9) |
|
|
| missing | 147 (26.1) |
| some either | 2613 (100) | measured | 2038 (78.0) |
|
|
| missing | 575 (22.0) |