junior college vs polytechnic

junior college

noun
  • An institution of higher education that awards the associate's degree but not bachelor's degree or higher. 

  • A government high school, usually abbreviated to "JC" 

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 

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