creative work vs opus

creative work

noun
  • A tangible manifestation of creative effort, such as literature, music, paintings, and software. 

opus

noun
  • A work, especially of art. 

  • A work of music or set of works with a specified rank in an ordering of a composer's complete published works. 

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