roll call vs rota

roll call

noun
  • The time of day fixed for such an event. 

  • Such an event in a legislative body in order to determine if a quorum exists. 

  • The subset of those members of a specific group who are present or available out of the full set of all the members of said group. 

rota

noun
  • A schedule that allocates some task, responsibility or (rarely) privilege between a set of people according to a (possibly periodic) calendar. 

  • A kind of zither, played like a guitar, used in the Middle Ages in church music. 

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