academic institution vs university

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. 

university

noun
  • Institution of higher education (typically accepting students from the age of about 17 or 18, depending on country, but in some exceptional cases able to take younger students) where subjects are studied and researched in depth and degrees are offered. 

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