elision vs missingness

elision

noun
  • The deliberate omission of something. 

  • The omission of a letter or syllable between two words or inside a word; sometimes marked with an apostrophe. 

  • A different mode or method of operating a computer program. 

missingness

noun
  • Absence. 

  • The manner in which data are missing from a sample of a population. 

  • Missing data; omission. 

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