The two biggest changes in the population pyramids of Germany in the periods of 1965 and 2015 are that in 1965 the population pyramid is well structured by age, while in 2015 the pyramid is increasing in size in its upper parts but becoming thinner in the lower parts.
In 1965 we have the ''baby boom'' period, where the birthrates went up, so there was a big percentage of young population. The population pyramid was wider at the bottom because of the high birthrates, slowly decreasing in the middle sections, and becoming smaller and smaller towards the upper parts.
In 2015 though, the population pyramid looks much different, with the middle section being the biggest, the lower part much thinner, and the upper part is also bigger. This is due to few reasons, like the shift from rural to urban population, pursuing of careers of the youngsters, being too expensive in the cities to rise more kids, and all of that contributed to a significant drop in the birthrates in the country. But also, it is worth mentioning, that the lifespan has increasing, so the population is aging and it is becoming older and older.
