post 31

more notes. I've pretty much gotten used to the note taking.

• life expectancy - the average number of years to be lived by a group of people born in the same year. 
• crude birth rate (cbr) number of births per 1000 of the population
• crude death rate (cdr) number of deaths per 1000 of the population.
• rate of natural increase (rni) produced by subtracting the number of deaths by the total number of births, this gives us the annual natural growth rate - in percentage form - for a country or region.
• net migration rate (nmr) the difference between the number of people entering and leaving a country during the year.