expert vs perfective

expert

adj
  • Extraordinarily capable or knowledgeable. 

  • Characteristic of an expert. 

noun
  • A player ranking just below master. 

  • A person with extensive knowledge or ability in a given subject. 

perfective

adj
  • Of, or relative to, the perfect tense or perfective aspect. 

noun
  • a perfective verb form 

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