duration vs trimester

duration

noun
  • An amount of time or a particular time interval. 

  • The time taken for the current situation to end, especially the current war 

  • A measure of the sensitivity of the price of a financial asset to changes in interest rates, computed for a simple bond as a weighted average of the maturities of the interest and principal payments associated with it. 

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. 

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