Today, we focused on measuring population.

Crude birth rate: number of births per 1000 of the population.

Crude death rate: number of deaths per 1000 of the population

Rate of natural increase (RNI)

• produced by subtracting the death rate from birth rate
• this gives us the annual natural growth rate- in percentage form-for a country or region.

An excess of persons entering the country is net immigration

An excess of persons leaving the country is net emigration

The difference between immigration and emigration during a year is net migration rate.

The net migration rate of US is 2.45 this year. The net migration of Mexico is -1.64 this year.

The most interesting fact I found in CIA is that Pitcairn Island has least population which is 48 people. That is even smaller than one Chinese class. People there make money by selling stamps.

Another interesting fact is that population of India is just 12 million fewer than China. But India has 19.89 birth rate which is 7 greater than China. And death rate for both countries is almost same, which means India will soon become the first country that has greater population than China.