| Variable | Level of significance (%) | ||||||
| Edu. status | BV + ve | % | BV ? ve | % | total | BV + ve | BV − ve |
| None | 0 | 0.0 | 3 | 1.7 | 3 | 0.0 - 6.5 | 0.4 - 4.9 |
| Primary | 7 | 12.7 | 14 | 8.0 | 21 | 5.3 - 24.5 | 4.4 - 13.1 |
| Secondary | 26 | 47.3 | 53 | 30.3 | 69 | 33.7 - 61.2 | 23.6 - 37.7 |
| Tertiary | 22 | 40.0 | 105 | 60.0 | 127 | 27.0 - 54.1 | 52.3 - 67.3 |
| Total | 55 |
| 175 |
| 230 |
|
|