sauna vs vaulting school

sauna

noun
  • The act of using a sauna. 

  • A very hot place or room. 

  • A room or a house designed for heat sessions. 

  • A public sauna. 

  • In some countries, a business with bath-like facilities that is actually a brothel or a place for (non-commercial) sexual encounters; a bathhouse. 

verb
  • To use a sauna. 

vaulting school

noun
  • Used other than figuratively or idiomatically: see vaulting, school. (A place where one learns to vault.) 

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