population pyramids

population pyramids: 

-> we use populations pyramids to anywise growth (or decline) of fertility, mortality, and a lot of immigration in all the different cities
-> males are always on the left of the charts
-> there are more women over the age of 80 than men
-> when we are talking about nations, there are three basic shapes:
1. the christmas tree- usually a developing nation; growth rates are slow, high birth rate, very short life expectancy such as namibia and bangladesh
2. the box- developing nation, slow growth; low infant mortality but slow population growth but they have a long life expectancy in countries such as sweeten and the USA
3. the cup- developed nation, negative growth; low birth rate, shrinking populations but yet still have a long life expectancy in places like italy and japan

-> ann arbor, michigan: very weird set up because there are barely any at the bottom or the top (older people and younger people) but there are a lot in the middle ( middle aged) because this is the location of university if michigan which is a huge campus with a lot of student and teachers.
-> for bragg, north carolina: nobody lives here past the age 45 because this is the military base and people usually are younger when living here and after 45 usually leave the military to hometowns.