mushrooming vs overestimate

mushrooming

noun
  • Rapid or explosive growth. 

  • The formation of a mushroom-like shape. 

  • The act of gathering mushrooms. 

overestimate

noun
  • An estimate that is too high. 

verb
  • To judge or calculate too highly. 

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