gymnasium vs prep school

gymnasium

noun
  • A type of secondary school in some European countries which typically prepares students for university. 

  • A large room or building for indoor sports. 

  • A public place or building where Ancient Greek youths took exercise, with running and wrestling grounds, baths, and halls for conversation. 

prep school

noun
  • A private or public school intended to prepare its students to get into prestigious universities. 

  • A private primary school which prepares its pupils for the common entrance examination most commonly at the age of thirteen, and subsequent entry into public school. 

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