copulate with vs trephine

copulate with

verb
  • to engage in sexual intercourse with someone 

trephine

verb
  • To perforate with a trephine. 

  • To use a trephine during surgery. 

noun
  • A surgical instrument with a cylindrical blade used to remove a circular section of tissue, f.e. bone or cornea; a trepan. 

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