At present,the total population of the world is about:

At the time of independence,our population was approximately ........... billion,which reached near ............ billion in the year $2000$ and crossed ........... billion in $2011$.

The study of human population statistically is known as

Choose the correct causes for the population growth.
$I$. Decline in death rate
$II$. Rapid increase in $MMR$ and $IMR$
$III$. Rapid decline in $MMR$ and $IMR$
$IV$. Increase in the number of people in the reproductive age group
$V$. Rapid increase in the death rate

Generally,there was a population growth rate increase in India,but in which of the following years was there a decrease in the population growth rate?

$A$: Every sixth person in the world is an Indian.
$R$: Life expectancy depends upon average life span.