letup vs tea break

letup

noun
  • A pause or period of slackening. 

tea break

noun
  • A short rest break which an employee is entitled to take, shorter in duration than a lunchbreak 

  • A short break or rest period during the day when a cup of tea or coffee is drunk. 

How often have the words letup and tea break occurred in a corpus of books? (source: Google Ngram Viewer )