quop vs throb

quop

verb
  • To throb or beat. 

throb

verb
  • To pound or beat rapidly or violently. 

  • To pulse (often painfully) in time with the circulation of blood. 

  • To vibrate or pulsate with a steady rhythm. 

noun
  • A beating, vibration or palpitation. 

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