polytechnic vs private school

polytechnic

noun
  • A three-year post-secondary vocational training institute, equivalent of community college in the U.S. or TAFE in Australia. 

adj
  • that teaches applied arts, sciences, technology, engineering and other academic subjects 

private school

noun
  • A fee-charging private or independent school. 

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