| Value | Category |
|---|---|
| 1 | no missing records |
| 2 | missing 2 |
| 3 | missing 2 & 3 |
| 4 | missing 2 & 3 & 1 |
| 5 | missing 2 & 4 & 1 |
| 6 | missing 2 & 4 |
| 7 | missing 2 & 3 & 4 |
| 8 | missing 2 & 1 |
| 9 | missing 3 |
| 10 | missing 3 & 4 & 1 |
| 11 | missing 3 & 4 |
| 12 | missing 3 & 1 |
| 13 | missing 1 |
| 14 | missing 1 & 4 |
| 15 | missing 4 |
| 99 | did not slot into categories |