Age Pyramids
file://pyramids.gif
Notes:
The birth rate in a population like Sweden has changed little for 50 years. Individuals grow older with their cohort. After age 60, the probability of dying increases for males earlier than for females
These data are 15 years old, when most baby boomers in the U.S. were still in High School, and Generation X was around First Grade.
Mexico has a young population, likely to lead to increased births as the children reach childbearing age.
Besides the age structure, socially influenced factors determining births and deaths are the fertility rate, defined as the average number of births per female in her lifetime, and the mortality rate, defined as the probability of an individual of given age dying during the coming year. The mortality rate responds to the general level of nutrition and health care available in the society.