demography
noun /dɪˈmɒɡrəfi/
  /dɪˈmɑːɡrəfi/
[uncountable]- the changing number of births, deaths, diseases, etc. in a community over a period of time; the scientific study of these changes- the social demography of Africa
 Word Originlate 19th cent.: from Greek dēmos ‘the people’ + -graphy.