Related Clues:
- Start of population explosion (not Big Bang)?
- Post-WWII birthrate increase
- Lots more kids, but only a little noise?
- Post-Second World War phenomenon
- Time for a lot of deliveries?
- Significant increase in the birth rate
- Temporary increase in birth rate
- Sudden higher birth rate
- Very little loud noise when multiple deliveries happen
- Surge in the birth rate