turn down vs upgrade

turn down

verb
  • To reduce the power, etc. of something by means of a control, such as the volume, heat, or light. 

  • To refuse, decline, or deny. 

  • To reposition by turning, flipping, etc. in a downward direction; to double or fold down. 

upgrade

verb
  • To improve the equipment or furnishings of or services rendered to 

  • To improve, usually applied to technology, generally by complete replacement of one or more components 

  • To replace with something better. 

  • To replace a program with a later version of itself, a version having a higher version number or marketed under a more recent product name. 

  • To improve in condition or status. 

noun
  • An upward grade or slope. 

  • An improvement 

  • An improved component or replacement item, usually applied to technology 

adv
  • Up a slope or grade. 

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