plenary session vs sederunt

plenary session

noun
  • A session of a conference or other meeting at which all members are expected to be present. 

sederunt

noun
  • Those people present at such a meeting. 

  • A formal meeting, especially of a judicial or ecclesiastical body. 

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