 |
| |
| Period | Africa | Asia | Central America | Europe | North America | Oceania | South America | Total number of countries |
|---|---|---|---|---|---|---|---|---|
| P1 | 4 | 6 | 2 | 21 | 2 | 2 | 10 | 47 |
| P2 | 4 | 4 | 2 | 22 | 2 | 2 | 10 | 46 |
| P3 | 6 | 4 | 5 | 24 | 2 | 2 | 9 | 52 |
| P4 | 8 | 6 | 6 | 28 | 2 | 2 | 9 | 61 |
| P5 | 7 | 7 | 4 | 30 | 2 | 2 | 9 | 61 |
| P6 | 5 | 10 | 3 | 34 | 2 | 2 | 8 | 64 |
| P7 | 4 | 9 | 4 | 34 | 2 | 1 | 9 | 63 |