populate vs ratchet up

populate

verb
  • To increase in number; to breed. 

  • To live in; to inhabit. 

  • To fill initially empty items in a collection. 

  • To supply with inhabitants; to people. 

  • To fill initially empty slots or sockets on a circuit board or similar. 

ratchet up

verb
  • to increase 

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