I calculated some travel statistics for Alex last night. In 4 years of life he has:
- Taken 42 flights
- Caught 14 different aircraft types (including subtypes)
- 11 different airlines (by AOC)
- Passed through 19 different airports
- Visited 12 countries (13 if you treat Hong Kong as separate from China)
By the end of next month he should have added 9 more flights, 1 more aircraft type, 3 more airlines, 5 more airports and another country (unless you treat Taiwan as China).
My stats at the same age were 2, 1, 1, 2, 1.