High Birth Rate
High Death Rate
Low Natural Increase
Natural increase is BR-DR. If both BR and DR is high, then NI is low.
This happens in the primitive stage, where the healthcare levels are low and therefore a lot of the children are dying and do not go to adulthood. Thus, people have a lot of kids to compensate for the lost kids. They also have a high BR due to high fertility, since women aren't as educated abd there is no contraception available. The nobles during this time may also think that by having many children they are more respected and looked up upon because it signals fertility.
Health care improves as science and technology improves. There is also an improvement in sanitation, more transport and medical care available. Thus, babies are more likely to survive and people are less susceptible to diseases and deaths. Hence the death rate falls.
However, people are still having a lot of children becacuse it is the current trend and they have not realized it.
Low death rate, and the birth rate declines. Hence slight increase in population. This is due to family planning, better education, and the realization that babies are now surviving more. Women are allowed to work by now and hence they don’t have enough time or resources to have more babies.
El Savador – high BR and increasing, will suffer from population momentum even if the total fertility rate falls
Stable population, death and birth rates are low due to low fertility and improved healthcare. Women are educated and thus won't bear as much children.
Higher DR than BR
Entering negative growth rate, population is decreasing.