illusion vs subjectivity

illusion

noun
  • The state of being deceived or misled. 

  • A misapprehension; a belief in something that is in fact not true. 

  • Anything that seems to be something that it is not. 

  • A magician’s trick. 

subjectivity

noun
  • The state of being subjective. 

  • A subjective thought or idea. 

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