| | | Very low IR < 7.2 | Low 7.2 < IR < 18.9 | High 18.9 < IR < 41.3 | Very high IR > 41.3 |
|---|
1
| Benin | 4 | 15 | 9 | 5 |
2
| Burkina Faso | 0 | 1 | 18 | 15 |
3
| Chad | 5 | 9 | 9 | 11 |
4
| Mali | 10 | 12 | 4 | 6 |
5
| Niger | 0 | 1 | 9 | 20 |
6
| Nigeria | 19 | 9 | 2 | 1 |
7
| Sudan | 18 | 2 | 6 | 4 |
8
| Togo | 8 | 14 | 7 | 2 |
- Classification of the meningitis dataset (34 annual values from 1966 to 1999 for 8 West African countries) into four categories according to log-Incidence Rate (log-IR) thresholds. Since the log-IR are normally distributed, the classification has been done according to quartile groups which divide the sorted data set into four equal parts, so that each part represents 1/4 of the sampled population. The IR range of the four resulting categories is shown in the first row.
