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

According to the $2001$ census,the population growth rate was approximately: (in $;\%$)

$Statement \; 1$: Zero population growth should be achieved as early as possible to control human population.
$Statement \; 2$: This requires not two children per couple but a little more effort on reduction of this number.

The main cause of population explosion in the world is:

The socio-religious cause of population growth is:

Per year growth in India's population according to the $1991$ census is (in $\%$)