hereditament vs heritability

hereditament

noun
  • Inheritance. 

  • Property which can be inherited. 

heritability

noun
  • The condition of being inheritable 

  • The ratio of the genetic variance of a population to its phenotypic variance; i.e. the proportion of variability that is genetic in origin 

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