coffee break vs entr'acte

coffee break

noun
  • A rest period during the business day (usually of about 10 or 15 minutes). So named because it is an opportunity to get coffee. 

entr'acte

noun
  • An interval between two acts of a play or opera. 

  • Another performance, such as a piece of music or a dance, during this. 

How often have the words coffee break and entr'acte occurred in a corpus of books? (source: Google Ngram Viewer )