trimester vs two bits

trimester

noun
  • A period of three months or about three months; (financial): quarter. 

  • One of the terms of an academic year in those learning institutions that divide their teaching in three roughly equal terms, each about three months long. Compare semester. 

two bits

noun
  • Twenty-five cents, or a quarter. 

How often have the words trimester and two bits occurred in a corpus of books? (source: Google Ngram Viewer )