proliferate vs reproduce

proliferate

verb
  • To increase in number or spread rapidly; to multiply. 

reproduce

verb
  • To generate or propagate offspring or organisms sexually or asexually. 

  • To bring something to mind; to recall. 

  • To produce again; to recreate. 

  • To produce an image or copy of. 

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