appertain vs involve

appertain

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

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

involve

verb
  • To comprise or include; to have as a related part. 

  • To take in; to gather in; to mingle, blend or merge. 

  • To cause or engage (someone or something) to participate or to become connected or implicated. 

  • To complicate or make intricate. 

  • To envelop, enfold, entangle. 

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