procreate vs work up

procreate

verb
  • To reproduce. 

  • To originate, create or produce something. 

  • To beget or conceive (offspring). 

work up

verb
  • To develop. 

  • To raise; to excite; to stir up. 

  • To give (a patient) a general medical examination to assess health and fitness. 

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