increase vs upgrade

increase

verb
  • To become more nearly full; to show more of the surface; to wax. 

  • To multiply by the production of young; to be fertile, fruitful, or prolific. 

  • To make (a quantity, etc.) larger. 

  • (of a quantity, etc.) To become larger or greater. 

noun
  • The creation of one or more new stitches; see Increase (knitting). 

  • For a quantity, the act or process of becoming larger 

  • Offspring, progeny 

  • An amount by which a quantity is increased. 

upgrade

verb
  • To replace with something better. 

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

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

  • 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. 

adv
  • Up a slope or grade. 

noun
  • An upward grade or slope. 

  • An improvement 

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

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