go bad vs upgrade

go bad

verb
  • Of foods and commodities, to spoil, rot, or otherwise become unusable due to age or storage conditions. 

  • Of a person or entity, to cease to be reputable and instead become delinquent, criminal, immoral, corrupt or poorly behaved. 

  • Of a geographic area, to become unsafe. 

upgrade

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

  • To replace with something better. 

  • 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 go bad and upgrade occurred in a corpus of books? (source: Google Ngram Viewer )