grievance vs recommendation

grievance

noun
  • A complaint or annoyance. 

  • A formal complaint, especially in the context of a unionized workplace. 

  • Feelings of being wronged; outrage. 

  • A wrong or hardship suffered, which is the grounds of a complaint. 

  • Violation of regulations or objectionable behavior. 

  • Something which causes grief. 

recommendation

noun
  • An act of recommending. 

  • A suggestion or proposal about the best course of action (with adpositions including "about" for the context and "to" for the course of action) 

  • That which is recommended. 

  • A commendation or endorsement. 

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