incompletion vs inefficacy

incompletion

noun
  • The state or quality of not being complete. 

  • A forward pass which is not caught inbounds by the intended receiver. 

  • Something which is not completed. 

inefficacy

noun
  • The condition of being ineffective 

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