oppression vs trigger point

oppression

noun
  • The exercise of authority or power in a burdensome, cruel, or unjust manner. 

  • The act of oppressing, or the state of being oppressed. 

  • A feeling of being oppressed. 

trigger point

noun
  • An event, arrangement, provocation, etc. that leads a certain, generally violent or angered, action to be taken. 

  • A hyperirritable spot in the skeletal muscle; a point in tender muscle that tends to elicit pain upon pressure or touch. ᵂᵖ 

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