The population pyramid of a country will also change through time as it develops. A country may improve health care and diet. It may, for example, invest in post natal care strategies and vaccination programmes for infant diseases to reduce infant mortality. As a result, people are likely to live longer and the pyramid will become wider through the age groups.
There are five clear shapes which indicate states of development - from the economically less developed stage (ELDC) to an economically developed one (EMDC) with a declining population.
Look at the shape of each pyramid and match it to a stage in the DTM.
