competency vs skillage

competency

noun
  • The ability to perform some task; competence. 

  • Implicit knowledge of a language’s structure. 

  • Meeting specified qualifications to perform. 

skillage

noun
  • The state of being highly skilled, the state of being skillful. 

  • The differentiating, or skilling, of call distribution based on an individual's skill level, expertise, or training. 

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