| Zone | Zone Leading Digit | % Correct |
|---|---|---|
| North America (NANP) | +1 | 100%
|
| Africa (Mostly) | +2 | 57%
|
| The Rest of Europe | +3 | 57%
|
| North-Central Europe | +4 | 57%
|
| Oceania & Southeast Asia | +6 | 57%
|
| Russia & Kazakhstan | +7 | 57%
|
| East Asia | +8 | 57%
|
| Middle East, South Asia, & Central Asia | +9 | 57%
|
| Central & South America | +5 | 43%
|