What was the world's total population during the $2011$ census?

The population growth of India from $1981$ to $1991$ is (in $\%$)

The population of India at the time of Christ was approximately

July $11$ is observed as

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 socio-religious cause of population growth is: