academic institution vs schooltime

academic institution

noun
  • An educational institution, dedicated to teaching and/or research. 

  • An educational institution, dedicated to higher education and research, that grants academic degrees. 

schooltime

noun
  • Time spent in school; classtime 

  • Time spent at school; schooldays 

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