appertain vs impute

appertain

verb
  • To belong as a part, right, possession, attribute, etc. 

  • To belong to or be a part of, whether by right, nature, appointment, or custom; to relate to. 

impute

verb
  • To attribute or credit to. 

  • To attribute or ascribe (responsibility or fault) to a cause or source. 

  • To replace missing data with substituted values. 

  • To take into account. 

  • To ascribe (sin or righteousness) to someone by substitution. 

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