coursebook vs syllabus

coursebook

noun
  • A textbook, a book designed to accompany a specific academic course, or one specified by the writers of the course to be read by its students. 

syllabus

noun
  • A summary of topics which will be covered during an academic course, or a text or lecture. 

  • The headnote of a reported case; the brief statement of the points of law determined prefixed to a reported case. 

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