omit vs slip through the cracks

omit

verb
  • To neglect or take no notice of. 

  • To delete or remove; to strike. 

  • To leave out or exclude. 

  • To fail to perform. 

slip through the cracks

verb
  • To escape notice or lack sufficient attention. 

How often have the words omit and slip through the cracks occurred in a corpus of books? (source: Google Ngram Viewer )