academic institution vs alma mater

academic institution

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

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

alma mater

noun
  • A school, college or university from which an individual has graduated or which he or she has attended. 

  • A school's anthem or song. 

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