cram school vs junior college

cram school

noun
  • A specialized school that trains students to meet particular goals, most commonly to pass the entrance examinations of high schools or universities. 

junior college

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

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

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