| Value | Category | Cases | |
|---|---|---|---|
| 0 | Not twin | 2286 |
95.1%
|
| 1 | Twin | 116 |
4.8%
|
| 2 | Second child but not twin | 0 |
0%
|
| 3 | One twin remaining in the study | 0 |
0%
|
| 4 | One child remaining | 0 |
0%
|
| 5 | miss | 3 |
0.1%
|