demography vs demology

demography

noun
  • The particular demographic makeup of a population. 

  • The study of the structure and population dynamics of other lifeforms, such as mammals, insects, plants, etc. 

  • The study of the characteristics of human populations, especially with regards to their makeup and fluctuations and the social causes behind these. 

demology

noun
  • demography 

How often have the words demography and demology occurred in a corpus of books? (source: Google Ngram Viewer )