proliferate vs sire

proliferate

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

sire

noun
  • A male animal that has fathered a particular offspring (especially used of domestic animals and/or in biological research). 

  • A lord, master, or other person in authority, most commonly used vocatively: formerly in speaking to elders and superiors, later only when addressing a sovereign. 

verb
  • to father; to beget. 

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