Phenomenal and rapid increase of population in a short period is called

Statement $1$: Human population doubles after every $35 \; \text{years}$ as against $200 \; \text{years}$ in $1600-1800$.
Statement $2$: Rapid increase is due to better health facilities.

The population of India at the time of Christ was approximately

What are the suggested reasons for population explosion?

The population explosion in India is due to:

The term population explosion means