institute vs middle school

institute

noun
  • An institution of learning; a college, especially for technical subjects 

  • An organization founded to promote a cause 

  • The person to whom an estate is first given by destination or limitation. 

  • The building housing such an institution 

verb
  • To invest with the spiritual charge of a benefice, or the care of souls. 

  • To nominate; to appoint. 

  • To begin or initiate (something); to found. 

middle school

noun
  • An educational level or stage between primary school and secondary school. 

  • A school which crosses the traditional divide between primary school and secondary school. 

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