Number of outliers dropped
| Country | Observations before removing the outliers (n) | Step 1: observations >30 international PPP dollars (n) | Step 2: observations >3× SD from the mean (n) |
| Botswana (2017) | 464 | 27 | 10 |
| Cameroon (2013) | 367 | 1 | 3 |
| Ethiopia (2016) | 498 | 12 | 5 |
| The Gambia (2017) | 792 | 6 | 5 |
| Kenya (2014) | 408 | 0 | 2 |
| Nigeria (2012) | 374 | 4 | 9 |
| Senegal (2015) | 184 | 0 | 2 |
| Tanzania (2018) | 288 | 2 | 0 |
| Uganda (2013) | 390 | 1 | 7 |
PPP, purchasing power parity.