frustrate vs slip through the cracks

frustrate

verb
  • To hinder or thwart. 

  • To cause stress or annoyance. 

  • To disappoint or defeat; to vex by depriving of something expected or desired. 

adj
  • ineffectual; useless; fruitless. 

slip through the cracks

verb
  • To escape notice or lack sufficient attention. 

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