| Suburban Wells | Year | |||
| 1989 | 1996 | 2006 | 2010 | |
| Keraniganj | 0.32 | 0.41 | 0.40 | 0.07 |
| Narayanganj | 0.41 | 0.46 | 0.31 | 0.36 |
| Savar | 0.28 | 0.19 | 0.30 | 0.15 |
| Savar_2 | 0.45 | 0.31 | 0.11 | 0.02 |