ache vs pricking

ache

noun
  • Continued dull pain, as distinguished from sudden twinges, or spasmodic pain. 

verb
  • To cause someone or something to suffer pain. 

  • To suffer pain; to be the source of, or be in, pain, especially continued dull pain; to be distressed. 

pricking

noun
  • A sensation that pricks. 

  • The act of piercing or puncturing with a sharp point. 

  • The driving of a nail into a horse's foot so as to produce lameness. 

  • A nicking. 

  • The mark or trace left by a hare's foot; a prick. 

  • The act of tracing a hare by its footmarks. 

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