riot vs serious

riot

verb
  • To cause to riot; to throw into a tumult. 

  • To annoy. 

  • To create or take part in a riot; to raise an uproar or sedition. 

noun
  • Wanton or unrestrained behavior or emotion. 

  • A humorous or entertaining event or person. 

  • A tumultuous disturbance of the public peace by a large group of people, often involving violence or damage to property. 

  • A wide and unconstrained variety. 

serious

adv
  • In a serious manner; seriously. 

adj
  • Committed. 

  • Without humor or expression of happiness; grave in manner or disposition 

  • Really intending what is said (or planned, etc); in earnest; not jocular or deceiving 

  • Important; weighty; not insignificant 

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