amok vs go postal

amok

verb
  • Synonym of run amok 

adv
  • In a frenzy of violence, or on a killing spree; berserk. 

  • Out of control, especially when armed and dangerous. 

noun
  • The act of running amok. 

  • One who runs amok; in Malay and Moro/Philippine culture, one who attempts to kill many others, especially expecting that they will be killed themselves. 

go postal

verb
  • To become aggressive and erratic, especially due to stress; specifically, to carry out a shooting spree at a workplace environment; also (more generally) to become very angry; to lose one's temper. 

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