Population Pyramid

Population pyramid is a graph which can show show us about the rate of male and female. Let me take an example, the African countries, most of countries of Africa have the highest rate of males and females. Especially the base of the population pyramid is very wide, because there are too many babies in African countries. there are almost three to four children per family. It can not show us the death rate and the born rate, but just at this time the number of each period population. And also, there are a lot  of pre-industriy from economy, which means these countries just machining some basic materials, that is cheap and no much profit. However, there are some countries such as US has the post-industry from economy, this kind of economy can make the highest profit by the easier way. Like Apple company and Microsoft.